JP2005092155A - Liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal display element by which a spacer for securely holding a gap between a couple of substrates can easily be manufactured. <P>SOLUTION: The method for manufacturing the liquid crystal display element is provided for manufacturing a liquid crystal display element having a couple of substrates 1 arranged across a fixed gap, the method including a procedure for arranging liquid resin material 2 between the surface of at least one of the substrate 1 and a stamper 4 having a plurality of recessed parts 3 formed on the surface opposite to the surface of the substrate 1 and forming a plurality of projections 7 on, for example, an ultraviolet-ray setting type liquid resin material by the recessed parts 3 and a procedure for setting the resin material 2 formed with the projections 7, for example, with ultraviolet rays. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display element in which a pair of substrates are arranged with a certain gap.

  In general, a liquid crystal display element is formed by bonding the inner periphery of a pair of electrode substrates through an adhesive resin called a seal. Spherical or fibrous spacers are scattered between the pair of electrode substrates to maintain a gap between them, but it is difficult to control the distribution density to be uniform. In particular, when a flexible plastic substrate is used as the substrate, it is necessary to apply a large amount of these spacers in order to keep the substrate interval constant. However, the dispersion of the application density causes a variation in cell thickness, There was a problem that the density of the disordered alignment would cause display unevenness.

As a method for making the spacer distribution density uniform, that is, for making the spacer existence probability uniform, a method is proposed in which the spacers are fixedly formed on the substrate instead of the dispersion. Examples of the method include a photolithography method in which a spacer made of resist is exposed and patterned at an arbitrary position, and a method described in Patent Document 1. This patent document 1 discloses a method of providing uneven “ridges” in pixel gaps by embossing on a substrate on which a plastic liquid crystal display element is formed in order to avoid a decrease in yield due to difficulty in fitting accuracy of the plastic substrate. Has been.
Japanese Patent Laid-Open No. 5-264882

  In the photolithography method described above, a resist material is used to form a spacer for sandwiching between two substrates, and patterning is performed to a specific shape using exposure and development, and the cross section shown in FIG. As shown schematically, spacers 22 made of resist are provided on the surface of the substrate 1. Here, as shown in FIG. 14B or FIG. 14C, the transparent electrode 12 may be provided between the spacer 22 and the substrate 1. Further, as shown in FIG. 14B, an alignment film 18 is provided on the surface of the transparent electrode 12 and the spacer 22, or as shown in FIG. 14C, the alignment film is interposed between the spacer 22 and the transparent electrode 12. 18 may be provided.

  This photolitho method can overcome the control of uniform spray density in the conventional wet or dry spacer particle spray method, but it requires an extra photolitho process, and the resist material used as the spacer is a solvent or liquid crystal material for alignment film printing. There are restrictions such as not dissolving. Also, substrate materials for plastic liquid crystal display elements are selected from materials that do not dissolve in solvents and liquid crystal materials during alignment film printing, such materials have poor adhesion, and spacers made of resist materials are mechanically There are problems such as peeling due to impact.

  Further, the one described in Patent Document 1 will be described in detail. First, as shown in FIG. 15 (a), the polymer resin 23 is injected into the submaster device 24, and as shown in FIG. 15 (b). The polymer resin 23 is covered with a polyester or polycarbonate film 24 as a release liner after the resin is smoothed and cured, and the polymer resin 23 is cured with ultraviolet rays. And the release liner 24 is peeled from the cured polymer resin 23 as shown in FIG. Here, in Patent Document 1, the functions of polyester and polycarbonate film 24 are not clear, but judging from the fact that they are described as “release liner”, it is clear that the film is not used for a liquid crystal substrate. It is. This means that there is no birefringence in order to use the film for liquid crystal applications, or in the case of an STN liquid crystal display element, a predetermined birefringent film can be used as a retardation compensation plate. It is clear from the fact that it is not described at all.

  Further, as shown in FIG. 16 (a), a method of directly embossing by pressing a submaster (mold) heated to 170 ° C. on the surface of a substrate 1 (polycarbonate, polyethersulfone, etc.) on which a plastic liquid crystal display element is formed. Exists. In this case, the method of directly embossing the plastic substrate has not only a problem of processing accuracy but also a problem of color unevenness associated with retardation in a liquid crystal using polarized light. This will be described in detail below.

(Machining accuracy)
In order to obtain a desired shape, the surface of the plastic substrate needs to be sufficiently melted to have a low viscosity. However, the substrate on which the liquid crystal display element is formed is thin, and it is extremely difficult to raise only the surface to Tg or more and close to the melting point, and as a result, the substrate itself is deformed. In order to avoid such a problem, it is necessary to perform pressure deformation in a high viscosity state. In this case, there arises a problem that the transfer accuracy of the embossing is lowered. In particular, for polymer substrates for liquid crystals, heat-resistant polymers are used in order to improve the alignment film processing and sealing material adhesion in the subsequent process, and only the surface of the heat-resistant polymer is raised above Tg to near the melting point. Is extremely difficult.

(Color unevenness)
When the above heat-resistant polymer is pressed and deformed in a state of high viscosity below the melting point, embossing is formed on a substrate made of a material that easily causes retardation due to internal stress (such as high optical elastic modulus) such as polycarbonate and polyether sulfone. The deformation traces of the portions are scattered as retardation, causing light loss and color unevenness, and degrading the quality of the display element.

  Furthermore, the following problems remain in each method described above.

(1). There is a possibility that the embossed shape may be deformed by the substrate constituent material being attacked by a chemical (resist solvent, developer, etchant, stripping solution) in the patterning process of the transparent electrode. In addition, when the substrate itself is embossed, the embossed portion is swollen and deformed by the solvent of the alignment film when the alignment film is applied, or the embossed portion is swelled by liquid crystal injected in a later process, and the embossed portion is the target spacer There is a problem that the function is impaired.

(2). Although “ridges” are provided between the pixel electrodes that drive the liquid crystal, it is difficult to accurately pattern the pixel electrodes in the gaps between the ridges formed by embossing. The shape of the rectangular pixel is deformed, and there is a problem of light omission or light shielding in the “ridge” portion in the pixel, which impairs display quality. In particular, supporting the counter substrate with the protrusions on one side substrate indicates that the “ridges” are aligned in a certain direction, and the substrate cannot be prevented from bending in a direction perpendicular to the “ridges”. .

  The present invention has been made in view of the above-described conventional problems, and the present invention relates to a liquid crystal display element capable of easily manufacturing a spacer capable of reliably holding a gap between a pair of substrates, a manufacturing method thereof, and a liquid crystal It is an object to provide a display element substrate and a manufacturing method thereof.

  The present invention has been made to solve the above problems, and a method of manufacturing a liquid crystal display element according to the present invention is a method of manufacturing a liquid crystal display element having a pair of substrates arranged with a constant gap, and at least Disposing a liquid resin material between a surface of one substrate and a stamper having a plurality of recesses formed on a surface facing the surface of the substrate, and forming a plurality of protrusions on the resin material by the recesses; And the procedure which hardens the resin material in which this protrusion was formed is characterized by the above-mentioned.

  In the manufacturing method of the liquid crystal display element according to the present invention having the above-described configuration, it is possible to hold the gap portion with the other substrate by the protrusion of the resin material, that is, the conventional spacer spraying process or the like. It is not necessary, and the function of the spacer can be provided by the protrusion of the resin material provided on the surface of the substrate. As described above, the protrusion is formed by the resin material covering the surface of the plastic substrate for the liquid crystal display element, so that the deformation of the protrusion due to the chemical or the liquid crystal material in the manufacturing process is prevented, and the spacer function is not impaired. According to the method, it is possible to prevent the conventional processing accuracy and color unevenness from occurring. In addition, the projections can be easily distributed uniformly in the pixels as compared with the conventional spraying method, and the action of holding the liquid crystal display elements uniformly is high, which is similar to that of plastic liquid crystal display elements. It is possible to reduce the feeling of roughness at the time of halftone display based on uneven cell thickness due to bending.

  A method for manufacturing a substrate for a liquid crystal display element according to the present invention is a method for manufacturing a substrate for a liquid crystal display element used in a liquid crystal display element having a pair of substrates arranged with a certain gap, A procedure in which a liquid resin material is disposed between a stamper having a plurality of recesses formed on a surface facing the surface of the substrate, and a plurality of protrusions are formed on the resin material by the recesses, and the protrusions are formed. The resin material is provided with a procedure for curing, and has the same advantages as the liquid crystal display element substrate according to the present invention.

  In the above manufacturing method, for example, there is a method in which a resin material is applied to the surface of the stamper where the concave portion is formed, the substrate is brought into contact with the surface applied with the resin material, and then the resin material is cured. Although the liquid crystal display element manufacturing method according to the present invention can be adopted, a procedure for applying a liquid resin material to the surface of at least one substrate, from the substrate surface coated with the resin material on the surface, to the contact surface It is preferable to provide a procedure for pressing a stamper having a plurality of recesses to form a plurality of projections on the resin material on the substrate surface and a procedure for curing the resin material having the projections formed thereon. Similarly, in the method for manufacturing a substrate for a liquid crystal display element according to the present invention, a procedure for applying a liquid resin material to the surface of the substrate, a concave portion is formed on the contact surface from the substrate surface on which the resin material is applied. It is preferable to provide a procedure for pressing a plurality of formed stampers to form a plurality of protrusions on the resin material on the substrate surface, and a procedure for curing the resin material on which the protrusions are formed.

  As the “substrate”, for example, a plastic substrate can be adopted, and as a liquid resin material to be applied, for example, there is no birefringence for a liquid crystal display element (retardation value is 10 nm or less). Liquid ultraviolet curable resins and ultraviolet curable resins are preferably used. In addition, as a method of curing the resin material on which the protrusions are formed, ultraviolet rays are irradiated from the substrate side to cure the ultraviolet curable resin, or a metal stamper is heated to form a thermosetting resin. A method of thermosetting is conceivable.

  Furthermore, in the manufacturing method according to the present invention, in the procedure of forming the protrusions, the protrusions are formed so that the density of protrusions in the parts other than the display pixels is higher than the density of protrusions in the display pixel parts. It is preferable to do.

  Accordingly, it is possible to prevent the distance between the substrates in the vicinity of the seal from becoming smaller than that of the display pixel portion when the pair of substrates is bonded. In particular, in the case of an STN liquid crystal display element that is sensitive to changes in cell thickness, it is not preferable that the difference in cell thickness between the display pixel area in the vicinity of the seal and the display pixel portion appears to be uneven. The quality of the STN liquid crystal display element can be improved by selectively improving the spacer density in the vicinity of the seal. Further, since the projections having the spacer function are distributed also in the display pixel portion, the liquid crystal display element can be prevented from being bent in a specific direction, and in particular, the cell thickness fluctuation due to the slight deflection of the substrate in the pixel can be suppressed.

  In the manufacturing method according to the present invention, it is preferable that the protrusions are not formed on the terminal portions, which eliminates the need for a particle removal step in terminal cleaning that is necessary in the conventional spraying method. Become.

More specifically, the density of the protrusions is 250 pieces / mm ² in the lighting display area (part where display pixels are gathered: dot matrix display part), and the display area (the area sandwiched between the periphery of the display pixels and the seal part). : Frame) 380 pieces / mm ² , seal area (area where upper and lower substrates are joined by a seal material) 500 pieces / mm ² , and terminal portions 0 pieces / mm ² are desirable. In the lit display area, when the spacer diameter is 12 μm and the density is 250 pieces / mm ² or more, the spacer is conspicuous in the pixel, and when it is 200 pieces / mm ² or less, the cell thickness varies due to the deflection of the substrate in the pixel. The pixel at the time of halftone display becomes rough. On the other hand, in the display area around the lighting display area, if the number is 380 / mm ² or more, a protrusion is formed on the wiring portion, resulting in disconnection, and therefore the density of existence is lower than that of the lighting display area. Is preferred. On the other hand, the seal area that seals a pair of substrates requires a sufficient amount of spacers (protrusions) to stick the upper and lower substrates together by fixing the sealing material with a hot press, and the protrusions in this seal area are arranged uniformly. By doing so, it is possible to inhibit the conductive particles mixed in the sealing material to connect the upper and lower substrates to be continuous in a continuous dumpling shape. That is, for example, when using conductive particles in which a terminal is provided on one substrate and conduction to the other substrate is mixed in a seal, the pair of upper and lower substrates are electrically connected by the conductive particles. If the mixing rate of the conductive particles is small, the number of contacts will decrease, leading to poor continuity between the upper and lower substrates. On the other hand, if a large amount of conductive particles are added, conduction will occur between the conductive particles, and an appropriate amount of conductivity will be generated. Even if particles are mixed, it is inevitable that a plurality of conductive particles are connected in a stochastic manner. However, if protrusions are provided in the seal area as described above, it is difficult to form a plurality of continuous dumplings. It can be tightened. For this reason, it is possible to increase the concentration of conductive particles in the seal, and as a result, it is easy to handle with fine pitch liquid crystal.

  Moreover, in the manufacturing method according to the present invention, it is preferable to adopt a configuration in which a transparent electrode is formed in a predetermined pattern on the surface of the cured resin material, and an orientation treatment is performed on the surface. A liquid crystal interposed between a pair of substrates can be driven by forming a transparent electrode in a predetermined pattern on a substrate from which protrusions functioning as spacers protrude. Furthermore, when adopting this configuration, it is preferable to adopt a configuration in which the transparent electrode is not formed on the protruding portion of the resin material, but is formed in a valley portion between the protrusions. Function can be demonstrated. In particular, in the present invention, it is possible to clean the substrate surface after such alignment treatment, unlike the conventional spacer spraying, so that the substrate surface can be cleaned immediately before the bonding of the substrates. Will improve. Further, since the formation of the transparent electrode is after the formation of the protrusion, there is no transparent electrode on the substrate side of the protrusion, and it is not necessary to consider that the spacer is peeled off from the transparent electrode as in the prior art.

  Further, in the manufacturing method according to the present invention, it is preferable that the shape of the protrusion is a columnar shape, and the height of the protrusion is formed from 1/5 to 1 time the width of the protrusion. Thereby, even if the columnar protrusion is formed in the pixel, the size is not recognized as a point defect, and the display quality of the liquid crystal display element can be improved. In general, the cell thickness of a liquid crystal display element is almost determined. For example, in the case of an STN liquid crystal display element, a cell thickness of 6 μm is generally used. In this case, since the height of the protrusion is 6 μm, if the width of the protrusion is 6 μm, the longitudinal section is preferably rectangular. On the other hand, when the width of the spacer is smaller than the height, the strength of the projection itself as the spacer is reduced, and the projection may be broken by partial pressurization of the panel surface. Further, if the width of the protrusion exceeds 5 times the cell thickness, that is, exceeds 5 times the height of the protrusion, it has sufficient strength, but the area occupied in the pixel becomes large and the function as a liquid crystal display element cannot be satisfied. . For this reason, as described above, the protrusion is preferably provided so that the height is about 1/5 to 1 times the width of the protrusion. In addition, when forming in such height, it is possible by forming the recessed part equivalent to the height of a protrusion in the stamper to be used. Further, when the shape of the protrusion is substantially cylindrical, the width means a diameter. Further, when protrusions are formed on both of the pair of substrates and the protrusions are in contact with each other, the height (total value) of the protrusions that contact each other is 1/5 of the width of the protrusion as described above. It is preferable that it is formed to be 1 to 1 times. Note that the height of the protrusion means the length of a portion protruding from another member (for example, a transparent electrode or an alignment film) formed in the valley portion of the substrate. Further, in the case where the width of the columnar protrusion is not constant, the width (diameter) means the maximum width. When the boundary between the protrusion and the bottom (valley part) is provided smoothly, the maximum width means the width at a position higher by 0.01 μm or more than the bottom (valley part). To do.

  Further, in the manufacturing method according to the present invention, in the step of forming the protrusion, the surface of the protrusion is engaged with the surface of the protrusion of the other substrate using a stamper in which the bottom of the recess is processed to be uneven. More preferably, the protrusion is formed on both of the pair of substrates so that the surface of the protrusion engages with the surface of the protrusion of the other substrate. It is preferable.

  Thereby, the surface of this protrusion can prevent the occurrence of deviation at the time of bonding the pair of substrates, and can improve the adhesive strength of the pair of bonded substrates. In particular, by providing protrusions in the seal area, for example, when anisotropically conductive particles coated with metal are dispersed in the seal material in the seal area to make the upper and lower substrates conductive, the anisotropically conductive particles are formed in a dump shape. It is possible to prevent leakage between lines due to the connection. Furthermore, there is an advantage that a member for adhering the substrates to be bonded is not necessarily required by the engagement of the protrusions provided outside the seal area as described above. In other words, a conventionally used spacer having an adhesive function is generally a hot-melt type low melting point thermoplastic resin, but this thermoplastic resin is used as a liquid crystal material. It had the problem of dissolving. In addition, the liquid crystal material impregnates this thermoplastic resin and has a problem of lowering the adhesion function. Further, when a thermal or photoreactive spacer is used as the spacer having the adhesion function, unreacted substances may be dissolved in the liquid crystal material, which causes a decrease in the function of the liquid crystal. On the other hand, by adopting the above configuration, the bonding strength of the upper and lower substrates can be supplemented by mechanically engaging the projections.

  The liquid crystal display element according to the present invention is a liquid crystal display element having a pair of substrates arranged with a certain gap, and at least one substrate is provided with a surface coating material on a surface facing the other substrate. The surface coating material has a plurality of protrusions protruding toward the other substrate, and the protrusions are in contact with the other substrate to maintain a distance between the pair of substrates. To do.

  In the liquid crystal display element according to the present invention having the above-described configuration, the gap portion with the other substrate can be held by the protrusion of the surface coating material, that is, without performing a conventional process such as spacer dispersion. In both cases, the projections can function as spacers. For this reason, by forming the protrusions with the resin material that covers the surface of the plastic substrate for liquid crystal display elements, deformation of the protrusions due to the chemicals or liquid crystal material in the manufacturing process is prevented, and the spacer function is not impaired. In addition, it is possible to prevent the problems of processing accuracy and color unevenness as in the prior art. In addition, the projections can be easily distributed uniformly in the pixels compared to the conventional dispersion type spacers, and the action of holding the liquid crystal display elements uniformly is high, which is similar to that of plastic liquid crystal display elements. It is possible to reduce the feeling of roughness at the time of halftone display based on the cell thickness non-uniformity due to the bending of the substrate.

  The substrate for a liquid crystal display element according to the present invention is a liquid crystal display element substrate used for a liquid crystal display element having a pair of substrates arranged with a certain gap, and the substrate has a surface coating material on the surface. The surface coating material has a plurality of protrusions protruding toward the surface side so as to contact the other substrate and maintain a distance between the pair of substrates. It can be used for the liquid crystal display element according to the present invention and has the advantages described above.

  In the liquid crystal display element according to the present invention and its substrate (hereinafter, simply referred to as “liquid crystal display element of the present invention”), for example, a plastic substrate is used as the substrate, as in the manufacturing method of the present invention. As the resin material, for example, a liquid ultraviolet curable resin or ultraviolet curable resin having no birefringence (a retardation value of 10 nm or less) for a liquid crystal display element is preferably used. In addition, as a method for forming the protrusion of the surface coating material as described above, for example, it is possible to use a stamper having a recess corresponding to the protrusion. Specifically, the stamper and the substrate are arranged with a certain gap. Then, a liquid resin material is interposed therebetween, and the resin material is cured to form the protrusions by the recesses. More specifically, for example, a liquid resin material is applied to a stamper, the resin material is brought into contact with the substrate, and the resin material in contact with the substrate is UV-cured or thermally cured, or the substrate surface It is possible to employ a technique in which a resin material is applied to the resin material, the resin material and a stamper are brought into contact with each other, and the resin material is ultraviolet-cured or thermally cured.

  Further, in the liquid crystal display element of the present invention described above, the protrusions are provided so that the density of protrusions other than the display pixels is higher than the density of protrusions of the display pixel parts. It is preferable to do.

  Accordingly, it is possible to prevent the distance between the substrates in the vicinity of the seal of the pair of bonded substrates from becoming smaller than the display pixel portion. In particular, in the case of an STN liquid crystal display element that is sensitive to changes in cell thickness, it is not preferable that the difference in cell thickness between the display pixel area in the vicinity of the seal and the display pixel portion appears to be uneven. The quality of the STN liquid crystal display element can be improved by selectively improving the spacer density in the vicinity of the seal. Further, since the projections having the spacer function are distributed also in the display pixel portion, the liquid crystal display element can be prevented from being bent in a specific direction, and in particular, the cell thickness fluctuation due to the slight deflection of the substrate in the pixel can be suppressed.

  In the liquid crystal display element of the present invention, it is preferable that the protrusions do not exist in the terminal portion, and this eliminates the step of removing particles in terminal cleaning, which is necessary in the conventional spraying method. In addition, it is preferable to comprise the density of a projection part similarly to the manufacturing method which concerns on this invention mentioned above.

  In the liquid crystal display element of the present invention, it is preferable that the surface coating material has a configuration in which a transparent electrode is provided on the surface facing the other substrate. Furthermore, when adopting this configuration, it is preferable to adopt a configuration in which the transparent electrode is not formed on the projection portion of the surface coating material, but is formed in a valley portion between the projections.

  In the liquid crystal display element of the present invention, the shape of the protrusion is preferably a columnar shape, and the height of the protrusion is preferably 1/5 times to 1 time the width of the protrusion. Thereby, even if the columnar protrusion is formed in the pixel, the size is not recognized as a point defect, and the display quality of the liquid crystal display element can be improved. Note that details are the same as the manufacturing method described above, and thus the description thereof is omitted.

  Further, in the liquid crystal display element of the present invention, the protrusion is formed on both of the pair of substrates, and the protrusion is formed in an uneven shape so that the surface engages with the surface of the protrusion of the other substrate. It is preferable that Thereby, the surface of this protrusion can not only prevent the occurrence of misalignment when the pair of substrates is bonded, but also improve the bonding strength of the pair of bonded substrates. Note that details are the same as the manufacturing method described above, and thus the description thereof is omitted.

  According to the present invention, the protrusions can be formed by the coating material covering the substrate surface, and the protrusions can be uniformly distributed in the pixels. Therefore, it is possible to uniformly hold the substrates forming the liquid crystal display elements. it can. Further, by increasing the protrusion density in the vicinity of the bonding seal portion to be higher than that in the pixel, it is possible to prevent the distance between the substrates in the vicinity of the bonding seal portion from being reduced, thereby improving the quality of the liquid crystal display element. . Moreover, the rigidity of the liquid crystal display element can be improved by adopting a structure in which the protrusions mesh with each other. Furthermore, by providing a concavo-convex shape at the seal portion on the outer peripheral portion of the panel, not only can the bonding be prevented from shifting, but also the adhesive strength can be improved. In addition, by providing protrusions on the sealing portion of the liquid crystal display element, for example, when anisotropically conductive particles coated with metal are dispersed in the sealing material to make the upper and lower substrates conductive, the anisotropically conductive particles are connected. Leakage between lines can be prevented.

  Hereinafter, embodiments for carrying out the present invention will be described.

Example 1 of the present invention will be described below with reference to the drawings. First, a method for manufacturing a substrate for a liquid crystal display device of Example 1 will be described.
1 to 3 are explanatory diagrams showing the manufacturing procedure of Example 1. FIG. 1 (a) shows a state where a liquid surface coating material is applied, and FIG. 1 (b) shows the state of (a). The procedure of pressing the mold against the substrate in the state is shown. FIG. 2 is an explanatory diagram for explaining a state in which ultraviolet irradiation is performed after the mold is pressed in the embodiment. FIG. 3 is an explanatory view showing a state in which the mold is detached after the resin is cured in the embodiment. FIG. 4 is an explanatory diagram for explaining each area in the liquid crystal display element. 5 to 8 are explanatory diagrams showing the manufacturing procedure of Example 1. FIG. 5 shows a state in which a transparent substrate is formed on the entire surface. FIGS. 6 and 7 show patterning on the formed transparent substrate. FIG. 8 shows an over-etched state, and FIG. 8B is an enlarged view. 9 and 10 are schematic cross-sectional views of the liquid crystal display element of the embodiment, FIG. 9 is an enlarged view of a main part, and FIG. 10 is an explanatory diagram for explaining the entire structure.

(Production method)
Example 1 is a procedure in which a liquid ultraviolet curable resin material is applied to the surface of one substrate 1 (a surface facing the other substrate) of a pair of plastic substrates 1 to be bonded, and the resin material is applied to the surface. A step of pressing a stamper 4 having a plurality of recesses 3 formed on the contact surface from the surface of the substrate 1 coated with the substrate to form a plurality of protrusions 7 on the resin material 2 on the surface of the substrate 1, and the protrusions 7 were formed. And a procedure for curing the resin material 2 with ultraviolet rays.

First, the manufacturing method of the stamper 4 will be outlined. For example, the stamper 4 can be manufactured by etching the quartz glass to form the cylindrical recess 3 having a depth of 6.2 μm and a diameter of 12 μm. The recesses 3 are for forming projections 7 on the surface of the substrate 1. The recesses 3 are formed with columnar projections 7 each having a lighting area of 250 / mm ² and a display area of 380 / mm ^2, the sealing portion 500 / mm ^2, are arranged uniformly in each area at a density such that the terminal unit 0 / mm ^2. More specifically, the manufacturing method of the stamper 4 will be described. A master (mold) can be obtained by forming nickel by about 100 μm on the quartz glass by electroforming and peeling it off from the quartz glass.

  In Example 1, as the plastic substrate 1, for example, a sheet-like polyethersulfone substrate having a birefringence value of 5 nm, a thickness of 0.2 mm, a width of 300 mm, and a length of 400 mm can be used. Then, a liquid ultraviolet curable resin 2 (for example, an acrylic hard coat liquid (trade name, manufactured by Mitsubishi Chemical Corporation) is applied to the surface of the substrate 1 at a thickness of about 10 μm using a bar coating method. The stamper 4 having the above-described recess 3 is pressed against the surface of the hard coat liquid 2 applied as shown in FIG. Then, the ultraviolet curable resin 2 is cured by irradiating the ultraviolet light 6 from the ultraviolet light source 5 from the plastic substrate 1 side. Thereafter, by separating the mold 4 from the hard coat 2, a plastic substrate in which the resin 2 is covered on the surface and the columnar protrusions 7 protrude from the surface as shown in FIG. 3 can be obtained.

  In this description, the plastic substrate has been described on the premise of a sheet-like substrate for explanation. However, the resin 2 is continuously applied using a roll-shaped film substrate, and the stamper 4 is sequentially pressed to cure the resin 2 with ultraviolet rays. Thus, it is possible to form a substrate having the columnar protrusions 7. In this case, as the stamper 4 serving as a mold, a thin metal having a recess 3 wound around a cylindrical member (drum-like member) can be used. It is also possible to employ a method of applying the resin 2 to a stamper. In addition to the method using ultraviolet curing, it is possible to cure by heating using a thermosetting resin.

Further, the protrusions 7 formed by the recesses 3 of the stamper 4 are uniformly distributed at a desired density in each area of the liquid crystal display element. Specifically, as shown in FIG. 4, the liquid crystal display element includes a lighting display area 8, a display area 9 around the lighting display area 8, a seal portion 10 around the display area 9, and an outside of the seal portion 10. However, in this embodiment, the density of the columnar protrusions 7 is 250 lighting areas / mm ² , 380 display areas / mm ² , and 500 seal parts, respectively. / Mm ² and 0 terminal portions / mm ² .

Here, in the lighting display area of 250 / mm ² , ten columnar protrusions exist in a pixel (pixel size: 200 μm square) with a pitch of 220 μm and an aperture ratio of 83%.

In this embodiment, the density of the columnar protrusions is 250 / mm ² , but the lower limit is when there are 5 columnar protrusions per pixel. When the number is 5 or less, the substrate is bent in the pixel. Generated and uneven, which was not preferable.

  Further, as shown in FIG. 5, a transparent electrode material 12 made of ITO was formed by sputtering on the surface of the hard coat material 2 on which a plurality of the columnar protrusions 7 were formed. In the figure, ITO 12 exists on the top of the columnar protrusion 7, but the ITO 12 is hardly formed on the side surface of the columnar protrusion 7.

  Then, as shown in FIG. 6, a positive resist 13 is applied to the surface of ITO 12 that is a transparent electrode with a thickness of 2 μm or less, and is exposed with ultraviolet rays 15 through a mask 14. The resist 13 is applied so that the columnar protrusions 7 penetrate from the resist 13. In this case, the resist 13 is not applied to the side surfaces of the columnar protrusions 7.

  Further, as shown in FIG. 7, the resist 13 applied to the substrate 1 is developed. In the illustrated example, the resist is partially removed. By performing wet etching in this state, the transparent electrode 12 in the portion 16 that has not been removed can be etched.

  Further, as shown in FIG. 8, by over-etching, the ITO 12 on the top of the columnar protrusion 7 is removed, and the resist 13 is peeled off. Here, the overetching amount 17 may be ½ or more of the diameter of the columnar protrusion. In this embodiment, the diameter of the columnar protrusion is 12 μm, and therefore, the overetching amount may be 6 μm or more. However, if the overetch amount 17 becomes excessive, the gap between the pixels, that is, the line spacing increases, and the aperture ratio decreases, so it is preferable that 1 μm is added to ½ the diameter of the columnar protrusion. .

  Next, an alignment film 18 is applied to the surface of the substrate 1 on which the transparent electrode 12 patterned as described above (the valley portion between the protrusions 7) is applied, and an alignment treatment is performed by a rubbing method. A display element substrate can be obtained. Then, the liquid crystal display element substrate thus manufactured is bonded to another counter substrate (see FIG. 9). This counter substrate is also the one in which the plastic substrate 1 is coated with the resin 2 as described above, and the transparent electrode 12 and the alignment film 18 are formed on the surface. The columnar protrusions as described above are not provided. In the drawing, an alignment film is not shown on the surface portion of the protrusion 7, but an alignment film may exist on the surface of the protrusion 7.

  Further, at the time of bonding, the sealing portion 10 of the substrate is provided in advance so as to seal the pair of substrates with an epoxy sealant 19 (see FIG. 10). Here, since the seal portion 10 of the present embodiment has the columnar protrusions 7, even when anisotropic conductive particles coated with metal are dispersed in the seal material and conduction between the upper and lower substrates is attempted, anisotropic conductivity is achieved. Leakage between lines due to the continuous conductive particles can be prevented.

(Liquid crystal display element)
In the liquid crystal display device manufactured by the above manufacturing method, of the pair of substrates 1 arranged with a certain gap, one substrate 1 is covered with a surface coating material 2 whose surface facing the other substrate is made of a resin material. The surface coating material 2 has a plurality of substantially cylindrical projections 7 projecting toward the other substrate. The columnar protrusion 7 protrudes to the other substrate side from the members (alignment film 18 and transparent electrode 12) formed on the surface of the substrate 1, and the protruding surface of the columnar protrusion 7 is the surface of the other substrate 1. By contacting the alignment film 18, the distance between the pair of substrates 1 is maintained. In addition, the protrusions 7 are provided such that the density of the parts other than the display pixels is higher than the density of the display pixel parts.

  Further, the substrate 1 has a patterned transparent electrode 12 formed below the alignment film 18, and this transparent electrode 12 is not formed on the portion where the protrusion 7 is formed (that is, the protrusion 7 has The transparent electrode 12 does not exist in the lower layer) and is formed in a valley portion between the protrusions 7.

Next, Embodiment 2 according to the present invention will be described below with reference to the drawings.
In addition, FIG. 11 shows the procedure of the manufacturing process of Example 2, and shows the state by which the surface coating material (liquid resin material) was formed in the board | substrate. 12 and 13 are schematic cross-sectional views for explaining the liquid crystal display element of the second embodiment. Note that description of portions having the same configurations and functions as those of the first embodiment is omitted.

  In the second embodiment, unlike the first embodiment, columnar protrusions are formed on a pair of substrates, and the surface shape of the protrusions (the shape of the protruding surface) meshes with the surface of the protrusions on the other substrate. It is provided in the shape.

  Here, the outline of the substrate manufacturing process is the same as that of the first embodiment. However, unlike the first embodiment, the stamper used for forming the protrusions has a plurality of groove shapes formed at the bottom of the recesses, whereby a plurality of irregularities 21 are provided on the surface of the protrusions. Here, as described above, the unevenness 21 is provided so as to mesh with the unevenness 21 of the projection of the other substrate. In this embodiment, a plurality of projections and depressions 21 are formed on the surface of one projection 7, but one depression is formed on the projection of one substrate, and one projection is formed on the projection of the other substrate. It is also possible for the dent and the convex portion to engage (fit) each other.

  The height of one of the columnar protrusions 7 is set to about ½ of the cell thickness of the final liquid crystal display element. In the present embodiment, the average height of the protrusions is 3.1 μm, the deepest portion of the surface of the columnar protrusion 7 is 1 μm, and the highest portion is 4.1 μm. The existence ratio of the columnar protrusions can be the same as that in the first embodiment. The alignment film 18 is provided not only on the valley portion of the protrusion 7 but also on the surface of the protrusion 7.

A third embodiment according to the present invention will be described below with reference to the drawings.
FIG. 13 is a schematic cross-sectional view for explaining the overall configuration of the liquid crystal display element of Example 3. In addition, the description is abbreviate | omitted about the part which has the structure and function similar to another Example.

  In the present embodiment, as shown in FIG. 13, protrusions 7 a that mesh with each other are formed by the surface coating material 2 in the seal portion 10 of the liquid crystal display element. The method of forming the substrate 1 is the same as that of the first embodiment, and the protrusion 7a of the seal portion 10 is not the columnar protrusion described above, but is a strip provided continuously along the edge of the liquid crystal display element. It is constituted by a body, and this surface is provided in a wave shape along the strip. In the present embodiment, the shape of the seal portion 10 increases the upper and lower substrate bonding areas and increases the bonding strength. Note that an epoxy seal material 19 is applied as a seal material to the protrusion 7 a of the seal portion 10.

  In addition, although each said Example employ | adopted the above-mentioned structure, this invention is not limited to this, A design change is possible suitably within the range which this invention intends.

It is explanatory drawing showing the manufacture procedure of Example 1, (A) shows the state which apply | coated the liquid surface coating material, (B) shows the procedure which presses a type | mold to the board | substrate of the state of (I). In the Example, it is explanatory drawing explaining the state which is performing the ultraviolet irradiation after pressing a type | mold. In the Example, it is explanatory drawing of the state which removed the type | mold after resin hardening. In the Example, it is explanatory drawing for demonstrating each area in a liquid crystal display element. In the Example, it is explanatory drawing which shows the state which formed the transparent substrate in the whole surface. In the Example, it is explanatory drawing which shows the state which patterns to the formed transparent substrate. In the Example, it is explanatory drawing which shows the state which patterns to the formed transparent substrate. In the same Example, it is explanatory drawing which shows the state which carried out the overetching, (b) is a schematic enlarged view of (a). It is a rough principal part expanded sectional view of the liquid crystal display element in the Example. It is a schematic expanded sectional view for demonstrating the whole structure of the liquid crystal display element in the Example. The procedure of the manufacturing process of Example 2 is shown, and the surface coating material is formed on the substrate. It is a schematic sectional drawing for demonstrating the liquid crystal display element of the Example 2. FIG. 6 is a schematic cross-sectional view for explaining a liquid crystal display element of Example 3. FIG. It is board | substrate sectional drawing for demonstrating the photolitho method which is a prior art. It is board | substrate sectional drawing for demonstrating the embossing method which is a prior art. It is board | substrate sectional drawing for demonstrating the embossing method which is a prior art.

Explanation of symbols

1 Substrate 2 Hard coat 3 Dent 4 type (stamper)
5 UV irradiation light source 6 UV light 7 columnar protrusion 7 a protrusion 8 lighting display area 9 display area 10 seal portion 11 terminal portion 12 transparent electrode 13 positive resist 14 mask 15 ultraviolet ray 16 resist removal portion 17 overetch amount 18 alignment film 19 seal 21 Concavity and convexity 22 on the top of the columnar protrusion Photolitho rib spacer 23 Polymer resin 24 Submaster device 25 Liner

Claims (28)

A method of manufacturing a liquid crystal display element having a pair of substrates arranged with a constant gap,
Disposing a liquid resin material between a surface of at least one substrate and a stamper having a plurality of recesses formed on a surface facing the surface of the substrate, and forming a plurality of protrusions on the resin material by the recesses ,
And the manufacturing method of the liquid crystal display element characterized by providing the procedure which hardens the resin material in which this protrusion was formed. A method of manufacturing a liquid crystal display element having a pair of substrates arranged with a constant gap,
A procedure for applying a liquid resin material to the surface of at least one substrate;
A procedure for forming a plurality of protrusions on the resin material on the substrate surface by pressing a stamper having a plurality of recesses formed on the contact surface from the surface of the substrate coated with the resin material on the surface,
And the manufacturing method of the liquid crystal display element characterized by providing the procedure which hardens the resin material in which this protrusion was formed. It is a manufacturing method of the liquid crystal display element of Claim 1 or 2, Comprising:
Producing a liquid crystal display element characterized in that, in the procedure of forming the protrusions, the protrusions are formed such that the density of protrusions in a part other than the display pixel is higher than the density of protrusions in the display pixel part. Method. It is a manufacturing method of the liquid crystal display element in any one of Claims 1 thru | or 3, Comprising:
A method of manufacturing a liquid crystal display element, comprising: forming a transparent electrode on a surface of the cured resin material in a predetermined pattern; performing an alignment treatment on the surface; and bonding a pair of substrates. It is a manufacturing method of the liquid crystal display element of Claim 4, Comprising:
A method of manufacturing a liquid crystal display element, wherein the transparent electrode is not formed in a protrusion portion of a resin material but in a valley portion between protrusions. A method for producing a liquid crystal display element according to any one of claims 1 to 5,
The method of manufacturing a liquid crystal display element, wherein the shape of the protrusion is a columnar shape, and the height of the protrusion is 1/5 times to 1 time the width of the protrusion. A method for producing a liquid crystal display element according to any one of claims 1 to 6,
Forming the protrusions on both of the pair of substrates;
In the step of forming the protrusion, a liquid crystal display, wherein a surface of the protrusion is formed to engage with the surface of the protrusion of the other substrate by using a stamper having a concave and convex portion formed on the bottom of the concave portion. Device manufacturing method.   A liquid crystal display element manufactured by the method for manufacturing a liquid crystal display element according to claim 1. A liquid crystal display element having a pair of substrates arranged with a certain gap,
At least one of the substrates is provided with a surface coating material on a surface facing the other substrate, and the surface coating material has a plurality of protrusions protruding toward the other substrate,
The protrusion is in contact with the other substrate to maintain a distance between the pair of substrates. The liquid crystal display element according to claim 9,
The liquid crystal display element is characterized in that the protrusions are provided so that the density of protrusions in a part other than the display pixel is higher than the density of protrusions in the display pixel part. The liquid crystal display element according to claim 9 or 10,
A liquid crystal display element, wherein the surface coating material is provided with a transparent electrode on a surface facing the other substrate. The liquid crystal display element according to claim 11,
The said transparent electrode is not formed in the protrusion part of a surface coating material, but is formed in the valley part between protrusions, The liquid crystal display element characterized by the above-mentioned. A liquid crystal display element according to any one of claims 9 to 12,
A liquid crystal display element, wherein the shape of the protrusion is columnar and the height of the protrusion is 1/5 to 1 times the width of the protrusion. A liquid crystal display element according to any one of claims 9 to 13,
The protrusions are formed on both the pair of substrates,
The liquid crystal display element, wherein the protrusion is formed in a concavo-convex shape so that a surface thereof is engaged with a surface of the protrusion of the other substrate. A method of manufacturing a substrate for a liquid crystal display element used in a liquid crystal display element having a pair of substrates arranged with a certain gap,
Disposing a liquid resin material between a surface of the substrate and a stamper having a plurality of recesses formed on a surface facing the surface of the substrate, and forming a plurality of protrusions on the resin material by the recesses;
And the manufacturing method of the board | substrate for liquid crystal display elements characterized by including the procedure which hardens the resin material in which this protrusion was formed. A method of manufacturing a substrate for a liquid crystal display element used in a liquid crystal display element having a pair of substrates arranged with a certain gap,
The procedure for applying a liquid resin material to the surface of the substrate,
A procedure for forming a plurality of protrusions on the resin material on the substrate surface by pressing a stamper having a plurality of recesses formed on the contact surface from the surface of the substrate coated with the resin material on the surface,
And the manufacturing method of the board | substrate for liquid crystal display elements characterized by including the procedure which hardens the resin material in which this protrusion was formed. A method for producing a substrate for a liquid crystal display element according to claim 15 or 16,
A substrate for a liquid crystal display element, characterized in that, in the procedure of forming the protrusions, the protrusions are formed such that the existence density of the protrusions other than the display pixels is higher than the existence density of the protrusions in the display pixel part. Manufacturing method. A method for producing a substrate for a liquid crystal display element according to claim 15 or 17,
A method for producing a substrate for a liquid crystal display element, comprising: forming a transparent electrode in a predetermined pattern on the surface of the cured resin material; and performing an alignment treatment on the surface. A method for producing a substrate for a liquid crystal display element according to claim 18,
A method of manufacturing a substrate for a liquid crystal display element, wherein the transparent electrode is not formed in a protrusion portion of a resin material but is formed in a valley portion between protrusions. A method for manufacturing a substrate for a liquid crystal display element according to any one of claims 15 to 19,
The method of manufacturing a substrate for a liquid crystal display element, wherein the shape of the protrusion is columnar and the height of the protrusion is 1/5 times to 1 time the width of the protrusion. A method for producing a substrate for a liquid crystal display element according to any one of claims 15 to 20,
In the step of forming the protrusion, a liquid crystal display element is formed such that the surface of the protrusion is engaged with the surface of the protrusion of the other substrate by using a stamper having a concave and convex portion formed on the bottom of the concave portion. Manufacturing method for industrial use.   A liquid crystal display element substrate manufactured by the method for manufacturing a liquid crystal display element substrate according to any one of claims 15 to 21. A liquid crystal display element substrate used in a liquid crystal display element having a pair of substrates arranged with a certain gap,
The substrate is provided with a surface coating material on the surface, and the surface coating material has a plurality of protrusions protruding toward the surface side so as to abut against the other substrate and maintain a distance between the pair of substrates. A substrate for a liquid crystal display element, comprising: A substrate for a liquid crystal display element according to claim 23,
The liquid crystal display element substrate according to claim 1, wherein the protrusions are provided so that a density of protrusions in a part other than the display pixel is higher than a density of protrusions in the display pixel part. A substrate for a liquid crystal display element according to claim 23 or 24,
A substrate for a liquid crystal display element, wherein a transparent electrode is provided on the surface side of the surface coating material. A substrate for a liquid crystal display element according to claim 25,
The transparent electrode substrate is a liquid crystal display element substrate, wherein the transparent electrode is not formed on the protruding portion of the surface coating material, but is formed in a valley portion between the protrusions. A liquid crystal display element substrate according to any one of claims 23 to 26,
A substrate for a liquid crystal display element, wherein the shape of the protrusion is columnar, and the height of the protrusion is 1/5 times to 1 time the width of the protrusion. A liquid crystal display element substrate according to any one of claims 23 to 27,
The substrate for a liquid crystal display element, wherein the protrusion is formed in a concavo-convex shape so that a surface thereof engages with a surface of the protrusion of the other substrate.

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