JP6022831B2 - Method for manufacturing liquid crystal device, liquid crystal device - Google Patents

Description

  The present invention relates to a liquid crystal device having a curved display surface and a manufacturing method thereof.

  Prior examples of liquid crystal devices (liquid crystal display devices) having a curved display surface are disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2009-86560 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2004-354468 (Patent Document 2). Yes.

  The liquid crystal display panel in the liquid crystal display device disclosed in Patent Document 1 basically has a structure in which a liquid crystal layer is sealed between a first substrate and a second substrate, which are preferably glass substrates. Yes. In this liquid crystal display panel, the first substrate and the second substrate described above in order to make the display surface curved, the light-transmitting property having a thickness of about 0.4 mm or less, preferably about 0.2 mm. A glass substrate is used. The thin pair of light-transmitting glass substrates may be formed by melting a thick glass plate with hydrofluoric acid or by mechanical polishing, and may be formed into a thin shape in advance. It is said that a glass plate may be used. The liquid crystal display panel thus manufactured is sandwiched between upper and lower frames formed in a curved shape, so that the liquid crystal display panel is fixed to a curvature radius substantially equal to these frames.

  As described above, when a very thin light-transmitting glass substrate is used to construct the liquid crystal display device disclosed in Patent Document 1, a process of melting glass using hydrofluoric acid, or mechanical polishing of thick glass is performed. This process requires a lot of work. On the other hand, when a liquid crystal display panel is manufactured by previously introducing a glass substrate having a thickness of 0.2 mm or less into a general production line, the yield is reduced due to glass breakage caused by the thinness of the substrate. There are concerns. In addition, since the liquid crystal display panel is bent by an external force that is sandwiched between the upper and lower frames, there is a possibility that unnecessary force is applied to the sealing material or the like that is originally cured in a state where each substrate is flat, which is also not preferable. Further, it is not preferable that some parts such as an upper and lower frame are required to fix the liquid crystal display panel in a curved shape, resulting in an increase in the number of parts.

  On the other hand, the liquid crystal display device disclosed in Patent Document 2 is a pair of a UV curable sealant and a mixture of a UV polymerizable monomer and a liquid crystal and a polymerization initiator for forming a polymer dispersed liquid crystal. It is manufactured by holding the flexible substrate in a curved state, irradiating ultraviolet rays from both the front and back surfaces of the flexible substrate held in the curved shape, and simultaneously curing the sealant and the mixture. However, in the manufacturing method according to the preceding example, a special manufacturing apparatus is required to hold the flexible substrate in a curved state and perform ultraviolet irradiation in that state, and the manufacturing line is significantly changed. It is not preferable.

  In addition, as a method for realizing a liquid crystal display device having a curved display unit other than the techniques disclosed in Patent Documents 1 and 2, it is also conceivable to use a glass substrate that has been processed into a curved shape in advance. However, since a high-temperature and high-pressure process such as press working is required to process a highly rigid material into a curved surface, it is not preferable because productivity is reduced. In addition, when performing a process such as applying a sealant, bonding substrates, and injecting liquid crystal using a curved glass substrate, a manufacturing apparatus different from a conventional manufacturing apparatus using a flat glass substrate is used. It is necessary to prepare and it is difficult to realize because it involves a significant change in the production line. Further, it can be considered that the liquid crystal display device after completion is exposed to a high temperature enough to bend the glass substrate to bend the display portion, but it is not realistic from the viewpoint of deterioration of components such as a sealing material and an alignment film.

JP 2009-86560 A JP 2004-354468 A

  A specific aspect of the present invention is to provide a technique capable of obtaining a liquid crystal device having a curved display portion without requiring a special manufacturing apparatus and without significantly changing a manufacturing line. One of them.

A method of manufacturing a liquid crystal device according to one aspect of the present invention is a method of manufacturing a liquid crystal device having a curved display surface, and (a) a plurality of spacers on one surface of a rigid substrate made of a flexible glass substrate. (B) a thermosetting sealing material is formed in a substantially annular shape on one surface of the hard substrate, and (c) a film substrate made of a resin film having a property of shrinking in one direction when applied with heat. be opposed across the sealing material on one surface of the substrate, (d) while the rigid substrate and the film substrate was pressed have line heat treatment for curing the sealing material, together shrinkage of the film substrate by the heat treatment It is bent the film substrate and the hard substrate by using a method of manufacturing a liquid crystal device comprising, injecting a liquid crystal material in the gap between the rigid substrate and the film substrate surrounded by the (e) sealing material A.

  According to said manufacturing method, a film substrate can be shrunk in one direction using the heat processing in the process in which a sealing material is hardened. At this time, since the hard substrate and the film substrate are fixed via a sealing material, the hard substrate is also bent together by utilizing the contraction force of the film substrate, and the curved substrate is bent in a concave shape as a whole. A liquid crystal device having a surface is obtained. According to such a manufacturing method, a conventional process using a hydrofluoric acid for thinning a glass substrate as an example of a hard substrate and a process by mechanical polishing are unnecessary, and a conventional liquid crystal device having a flat plate structure It is possible to manufacture a liquid crystal device having a curved display surface with the same manufacturing equipment. Furthermore, in the past, a special housing or the like was required to maintain the curved state of the liquid crystal device. According to the manufacturing method of the present invention, the curved state is maintained without using such a housing. It is possible.

  In the manufacturing method described above, the overlapping region of the hard substrate and the film substrate has a length in the long side direction of 4 times or more compared to the length in the short side direction, and the shrinking direction of the film substrate corresponds to the long side direction. It is preferable.

  Thereby, the whole hard board | substrate and a film board | substrate can be bent more favorably.

In the above manufacturing method, (b) forms a first sealing material that is cured at a relatively high temperature and a second sealing material that is cured at a relatively low temperature, and (d) is a relatively low temperature. It is also preferable to perform a relatively high temperature heat treatment after the heat treatment. The above (d) is also preferably performed by arranging a dummy substrate outside the film substrate.

  As a result, when the low temperature heat treatment is performed, the hard substrate and the film substrate are fixed relatively flat without bending so much, and then the hard substrate and the film substrate are fixed more firmly while being bent by the high temperature heat treatment. Therefore, peeling of the hard substrate and the film substrate can be prevented more reliably.

  In the manufacturing method described above, in (a), it is more preferable to form a plurality of spacers by forming a resin film on one surface of the hard substrate and patterning the resin film.

  Thereby, a plurality of columnar spacers made of a resin film is obtained on one surface of the hard substrate. In such a plurality of columnar spacers, the spacers do not move or aggregate, so that when the film substrate and the hard substrate are bent, the cell thickness is less likely to be uneven due to the uneven number of spacers per unit area.

A liquid crystal device according to one embodiment of the present invention is a liquid crystal device having a curved display surface, and (a) a hard substrate made of a flexible glass substrate , and (b) applying a certain amount of heat. A film substrate made of a resin film having a property of shrinking in one direction, (c) a thermosetting sealing material provided in a substantially annular shape between each surface of the hard substrate and the film substrate, and fixing the both; And (e) a liquid crystal layer disposed between the hard substrate and the film substrate, and (e) a liquid crystal layer disposed between the hard substrate and the film substrate.

  According to this configuration, a liquid crystal device having a curved display surface that can be manufactured with the same manufacturing equipment as that of a conventional liquid crystal device having a flat plate structure is obtained. In addition, a special housing or the like is not required to maintain the curved state of the liquid crystal device, and the configuration can be simplified as compared with the conventional case.

1A is a schematic perspective view of a liquid crystal display device according to an embodiment, FIG. 1B is a schematic cross-sectional view of the liquid crystal display device, and FIG. 1C is a view of the liquid crystal display device. It is a figure for demonstrating arrangement | positioning of a polarizing plate. 2A to 2F are schematic cross-sectional views illustrating an example of a method for manufacturing a liquid crystal display device. 3A to 3C are schematic cross-sectional views illustrating an example of a method for manufacturing a liquid crystal display device. FIG. 4 is a cross-sectional view showing the structure of the columnar spacer. FIG. 5 is a schematic plan view for explaining one step in the manufacturing method of the liquid crystal display device. 6A to 6B are schematic cross-sectional views illustrating an example of a method for manufacturing a liquid crystal display device. FIG. 7 is a schematic cross-sectional view of the liquid crystal display device.

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

  1A is a schematic perspective view of a liquid crystal display device according to an embodiment, FIG. 1B is a schematic cross-sectional view of the liquid crystal display device, and FIG. 1C is a view of the liquid crystal display device. It is a figure for demonstrating arrangement | positioning of a polarizing plate. In the liquid crystal display device 1 shown in FIG. 1A, the display surface 2 is curved in a concave shape when viewed from the front. The liquid crystal display device of the present embodiment uses the phenomenon that the film substrate 12 contracts in one direction and curls greatly in the heat treatment process (firing process) for curing the sealing material 14, and thus the curved display surface 2. To realize. Details of the manufacturing method will be described later.

  As shown in FIG. 1B, the liquid crystal display device 1 includes a glass substrate (hard substrate) 11, a film substrate 12, a plurality of columnar spacers 13, a sealing material 14, a liquid crystal layer 17, a back side polarizing plate 21, and a front side polarizing plate. 22 is comprised. Although not shown in the figure, a transparent electrode patterned as an electrode for displaying a segment pattern or a dot display pattern is disposed on each inner surface side of the glass substrate 11 and the film substrate 12, on which An alignment film is also formed.

  The glass substrate 11 is formed in a curved surface shape and is disposed on the back surface side with respect to the display surface 2. The glass substrate 11 is selected from the viewpoints of flexibility and handling. For example, it may be considered that a soda-lime glass substrate containing more impurities has a lower strength than a non-alkali glass substrate (or a low alkali glass substrate) with few impurities if the plate thickness is the same. In the case of an alkali-free glass substrate, the plate thickness is preferably about 0.3 to 0.5 mm, more preferably about 0.3 to 0.4 mm. In the case of a soda lime glass substrate, the plate thickness is preferably about 0.4 to 0.7 mm, and more preferably about 0.4 to 0.6 mm. Whichever material is used, if the thickness of the glass substrate 11 is too thin, the possibility of cracking is high and handling is difficult, but conversely, if the plate thickness is too thick, the curling force (bending force) caused by the film substrate 12. Is offset by the strength of the glass substrate 11, and the curl effect is difficult to obtain.

  The film substrate 12 is made of a resin film such as a polycarbonate film. The film substrate 12 is required to have such properties that the in-plane retardation can be reduced, the heat resistance is high enough to form a transparent electrode on one surface, and the film shrinks in one direction and curls when fired at a high temperature.

  Each columnar spacer 13 is disposed between the glass substrate 11 and the film substrate 12 and is used to maintain the gap. Each columnar spacer 13 can be formed by, for example, a photolithography technique using a photosensitive resin. Each of the columnar spacers 13 has a tapered cross-sectional shape, and the shape in plan view observed from the normal direction of the substrate is a substantially rectangular shape, a substantially rhombus shape, a substantially circular shape, and the like. Are arranged. Since each of the columnar spacers 13 is formed in close contact with the glass substrate 11 side, each columnar spacer 13 is dragged by the shrinkage of the film substrate 12 when the sealing agent 14 is baked during the manufacturing process of the liquid crystal display device 1. Does not move in the plane. Therefore, it is effective to suppress the occurrence of in-plane deviation in the area occupied by the unit area due to the aggregation or movement of the columnar spacers 13 and to keep the gap (cell thickness) between the substrates uniform. Instead of each columnar spacer 13, for example, a spherical gap material sprayed by a dry spraying method or the like may be used.

  The sealing material 14 is provided so as to surround a region where the glass substrate 11 and the film substrate 12 overlap each other in a substantially annular shape in a plan view, fix the glass substrate 11 and the film substrate 12 to each other, and fix the liquid crystal layer 17. Is sealed. The sealing material 14 needs to withstand high temperatures and have an adhesive strength sufficient to fix both the glass substrate 11 and the film substrate 12. For example, an epoxy thermosetting sealing material is preferably used.

The liquid crystal layer 17 is formed by filling a liquid crystal material between the glass substrate 11 and the film substrate 12. The alignment mode of the liquid crystal layer 17 is not particularly limited, and may be, for example, a vertical alignment mode in which liquid crystal molecules are aligned substantially perpendicular to the substrate surface, a TN (Twisted Nematic) mode, or an STN (Super Twisted) mode. Nematic) mode, IPS (In-Plane)
Switching) mode or the like.

  The back side polarizing plate 21 is disposed outside the glass substrate 11. The front side polarizing plate 22 is disposed outside the film substrate 12. As shown in FIG. 1C, the absorption axis direction a1 of the back-side polarizing plate 21 is set along the longitudinal direction of the liquid crystal display device 1, and the absorption axis direction a2 of the front-side polarizing plate 22 is the liquid crystal display device. 1 is set along the short direction. Note that the positional relationship between the directions a1 and a2 may be reversed. Further, an alignment processing direction (for example, rubbing direction) a3 applied to the alignment film (not shown) of the glass substrate 11 is set to a direction a3 from the left to the right in the drawing along the longitudinal direction of the liquid crystal display device 1, for example. (The reverse direction is also acceptable.) The shrinking direction a4 of the film substrate 12 is set to be parallel to the alignment processing direction a3. Usually, the film substrate 12 is subjected to a stretching process, and the direction of the stretching process coincides with the shrinkage direction a4 described above.

  Next, a method for manufacturing the liquid crystal display device 1 of the present embodiment will be schematically described. As described above, in the liquid crystal display device 1 of the present embodiment, the glass substrate 11 and the film substrate 12 are bonded to each other with the sealing material 14 interposed therebetween, and the film substrate 12 contracts greatly in the process of firing the sealing material 14 at a high temperature. A curved display surface 2 is realized by utilizing the phenomenon of curling. At this time, in order to firmly bond the curled film substrate 12 and the glass substrate 11 in a pressing jig, the glass substrate 11 is pulled by the force of the curled film substrate 12, and the glass substrate 11 follows the film substrate 12. Thus, the curved display surface 2 is obtained by bending. The curled film substrate 12 basically does not return to its original straight shape even when it is returned to room temperature, so that its curved shape is maintained after it is removed from the pressing jig. From the viewpoint of such a manufacturing method, the display surface 2 of the liquid crystal display device 1 preferably has a horizontal length larger than its vertical length. More specifically, the aspect ratio of the display surface 2 is 1: 4. It is preferable that there is more.

  Here, a method for controlling the curvature of the display surface 2 of the liquid crystal display device 1 will be described. In order to change the curvature of the display surface 2, a method of changing the shrinkage rate by selecting the material of the film substrate 12 itself can be considered. If the material of the film substrate 12 is the same, the curvature of the display surface 2 can be changed by changing the thickness of the film substrate 12. The greater the thickness of the film substrate 12, the greater the force due to curling during contraction.

  The curvature can also be controlled by changing the thickness of the glass substrate 11. Moreover, the curvature of the display surface 2 can be changed also by changing the heating temperature at the time of baking of the sealing material 14 in the temperature range that the film substrate 12 can withstand. That is, if the material of the film substrate 12 is the same, the higher the temperature, the greater the curling force.

  In addition, the curvature can be changed by annealing the film substrate 12 in advance. The curvature of the display surface 2 is slightly smaller than when the annealing is not performed. The film substrate 12 that has been annealed once retains its curled shape after shrinkage, and it is straightly (horizontally) bonded to the unsealed sealing material 14 and the glass substrate 11, so that it curls even at the same firing temperature. The power is slightly reduced.

  From the above, it is the firing temperature of the sealing material 14 that is greatly effective in controlling the curvature of the display surface 2, but annealing the film substrate 12 itself can also be used for controlling the curvature. An experiment was conducted to confirm the influence of the firing temperature of the sealing material 14 and the presence or absence of annealing on the film substrate 12. As a result, (1) the firing temperature of the sealing material 14 was 150 ° C., and the film substrate 12 was not annealed. ) The firing temperature of the sealing material 14 is 150 ° C. and the film substrate 12 is annealed, (3) The firing temperature of the sealing material 14 is 120 ° C. and the film substrate 12 is not annealed, and (4) The firing temperature of the sealing material 14 is There was annealing to 120 ° C. and the film substrate 12, and a large curvature was obtained in the order of.

  Also, the direction of the curved surface depends on the direction of curling due to the shrinkage of the film substrate 12, so it is conceivable to change the curling direction as one means, and the curling direction is different (for example, a coating having a different shrinkage rate on the film). It is also conceivable to prepare a film). Although it is in the direction of curvature, it is considered that a deviation occurs in the volume reduction due to the crystallization inside the polymer material of the film substrate 12 by heating, which leads to curling. The deviation in volume reduction is considered to be mainly caused by the stretching process and the flow process in film production.

  In addition, when a transparent conductive film such as ITO (Indium Tin Oxide) is formed on one surface of the film substrate 12, it is assumed that the shape thermal stability of the transparent conductive film is high. The surface provided with the conductive film is convex (concave when viewed from the display surface 2 side). However, it may be desired to have a convex shape when viewed from the display surface 2 side. In that case, the electrode pattern of the glass substrate 11 may be reversed and the components of the liquid crystal display device may be arranged so that the glass substrate 11 side is the display surface 2.

  Examples of the liquid crystal display device and its manufacturing method will be described below.

Example 1
2A to 2F and FIGS. 3A to 3C are schematic cross-sectional views illustrating an example of a method for manufacturing a liquid crystal display device. FIG. 4 is a cross-sectional view showing the structure of the columnar spacer. FIG. 5 is a schematic plan view for explaining one step in the manufacturing method of the liquid crystal display device. Here, it is assumed that a large number of liquid crystal devices are simultaneously formed on a large-sized substrate and divided later (so-called multi-face drawing).

  First, a mother glass substrate 111 made of non-alkali glass having a thickness of 0.3 mm is prepared as a base material of the glass substrate 11, and an ITO film is formed on one surface of the mother glass substrate 111 with an in-line sputtering apparatus to a thickness of 200 nm. A shaped electrode was produced by a photolithography process and a wet etching process. Note that illustration of electrodes is omitted.

  Next, a non-conductive black light-shielding resin solution having negative photosensitivity is applied on one surface of the mother glass substrate 111 with a spinner at 1250 rpm for 30 seconds, and then on a hot plate at 100 ° C. for 15 seconds. Temporary firing was performed under the conditions. The resin film obtained by pre-baking was exposed to 200 mJ with a contact exposure machine through a photomask. After exposure, immersion development is performed with a 0.1% aqueous solution of TMAH (tetramethylammonium hydroxide), and the developer and pure water are replaced by rinsing with pure water, the mother glass substrate 111 is dried, and an oven at 240 ° C. For 20 minutes. In the photomask, exposure patterns corresponding to rhombus-shaped columnar spacers each having a side of 20 μm were arranged at a pitch of 100 μm vertically and horizontally.

  Next, a negative translucent photosensitive resin was applied with a spinner at 900 rpm for 30 seconds, and pre-baked at 100 ° C. for 120 s on a hot plate. Then, 200 mJ exposure was carried out with the contact | adherence exposure machine through the photomask of the same pattern as what was used at the time of exposure of the resin film which consists of an above-mentioned nonelectroconductive black light shielding resin solution. After exposure, immersion development is performed with a 1% aqueous solution of TMAH (tetramethylammonium hydroxide), and the developer and pure water are replaced by rinsing with pure water, the mother glass substrate 111 is dried, and the oven is heated at 220 ° C. Baked for 30 minutes. As a result, a plurality of columnar spacers 13 were formed on one surface of the mother glass substrate 111 as shown in FIG. As shown in FIG. 4, each columnar spacer 13 is composed of a lower layer side black light shielding resin film 13a and an upper layer side light transmissive resin film 13b, and is a laminated film having a tapered cross section. The film thickness of each columnar spacer 13 was about 3.3 μm from the measurement results of the stylus type step gauge. The black light-shielding resin film 13a is used for improving display quality, but it may be omitted, and the columnar spacer 13 may be configured using only the translucent resin film 13b.

  On the other hand, as a base material for the film substrate 12, a mother film substrate 112 having a thickness of about 120 μm is prepared in which a transparent conductive film of 30 Ω / sq. Is formed on the entire surface of a polycarbonate film having a very small in-plane retardation. This was bonded to a support substrate 113 having a thickness of 0.7 mm (see FIG. 2B). The reason for this is to facilitate handling of the mother film substrate 112 in a later step. Next, an electrode is formed by patterning the transparent conductive film of the mother film substrate 112. The patterning of the electrode may be performed by a photolithography process and an etching process, but the manufacturing process can be shortened by a laser etching method in which the transparent electrode is evaporated and directly patterned by irradiating a laser beam. This method is effective when using a film material made of a material having poor resistance to acidic chemicals such as hydrochloric acid, sulfuric acid, and ferric chloride used in the wet etching process, and widens the selection range of the material of the film substrate 12. Can do. The shrinkage rate of the mother film substrate used in this example is 180 ° C. and 0.1%. As a preliminary experiment, a film substrate having a size of 100 mm × 250 mm was annealed at 180 ° C. for 1 hour, and this was returned to room temperature and observed. As a result, it was confirmed that the film substrate was curled with a radius of curvature of about 150 mm.

  Next, as shown in FIG. 2 (C), a vertical alignment film material having a surface free energy of 35 to 38 mN / m is printed on one surface of the mother glass substrate 111 into a seal frame by flexographic printing, and is subjected to 90 ° C. The vertical alignment film 15 was formed by pre-baking under the conditions of 15 minutes and further baking at 180 ° C. for 30 minutes. Similarly, as shown in FIG. 2D, a vertical alignment film material having a surface free energy of 35 to 38 mN / m is printed on one surface of the mother film substrate 112 by a flexographic printing method into a seal frame. The vertical alignment film 16 was formed by pre-baking at 15 ° C. for 15 minutes. It should be noted that the vertical alignment film 16 formed without the main alignment substrate material of the mother film substrate 112 being fired has an influence on the alignment of the liquid crystal layer 17, but there is no particular problem with the display quality. I have confirmed. Thereafter, only the mother glass substrate 111 was rubbed. The rubbing conditions were a roller to which a cotton rubbing cloth having a thickness of about 3 mm was bonded, an indentation amount of 0.6 mm, a rubbing speed of 75 mm / sec, and a roller rotation speed of 1000 rpm.

  Next, as shown in FIG. 5, a cut line 115 corresponding to a region to be the glass substrate 11 later was formed on the mother glass substrate 111 by a scriber. At this point, the cut line 115 was inserted but braking was not performed. Here, a blank area 116 is further provided on each of the left and right sides of the area to be the glass substrate 11.

  Next, as shown in FIG. 2 (E), a seal material 14 in which 2 wt% of silica particles having a particle size of 3.2 μm are mixed is applied on one surface of a mother glass substrate 111 with a dispenser in a substantially annular shape (frame shape). . The sealing material 14 was formed inward by 1 mm from the in-plane region outer shape frame where the glass substrate 11 and the film substrate 12 overlap. However, in the conductive pad portion for conducting between the glass substrate 11 and the film substrate 12, 2 wt% of gold-coated plastic particles having a particle size of 3.5 μm is mixed in addition to the silica particles. Further, a portion where the sealing material 14 does not exist is provided in a portion corresponding to the right side of the liquid crystal display device. This location is used as an injection port when a liquid crystal material is vacuum-injected in a later process.

  After the application of the sealing material 14 is completed and the sealing material 14 is temporarily baked for about 5 minutes, the mother glass substrate 111 is braked along the cut line 115 shown in FIG. The size of each of the plurality of glass substrates 11 obtained by braking is 130 mm in the horizontal direction and 28 mm in the vertical direction (of which the electrode portion is 3 mm). If the subsequent process is performed with the mother glass 111 left without braking, the film substrate 12 contracts for each imposition corresponding to each glass substrate 11 and the glass substrate 11 side breaks. Yield may be worse. For this reason, it is preferable to perform braking before bonding the glass substrate 11 and the film substrate 12 as in this embodiment.

  Next, by cutting the mother film substrate 112 that has been pre-baked at 90 ° C., a plurality of film substrates 12 having a size that is 3 mm smaller in the vertical direction than the glass substrate 11 (that is, 130 mm in the horizontal direction and 25 mm in the vertical direction). Formed. Then, the film substrate 12 is overlaid on the glass substrate 11 as shown in FIG. 2 (F), and a dummy glass substrate 114 is arranged on the other side of the film substrate 12 as shown in FIG. 3 (A). The ultraviolet curable sealant 117 was formed in the blank area 116 in the above, and each glass substrate 11 and the dummy glass substrate 114 were temporarily fixed. The width of the margin area is about 10 mm on each of the left and right sides. The film substrate 12 has a thickness of about 120 μm. If the width of the blank area 116 is longer than necessary, a crack may enter there and the crack may be affected.

Next, the sealing material 14 was baked under conditions of 150 ° C. and 30 minutes while applying a constant pressure between each glass substrate 11 and the dummy glass substrate 114 with a pressing jig. The pressing jig has a rubber sandwiched between metal plates, and the pressing pressure is 1.1 kgf / cm ² .

  Next, as shown in FIG. 3B, the blank area 116 temporarily fixed using the ultraviolet curable sealant 117 was cut with a scriber. Here, it is only necessary to cut only the glass substrate 11 side, but at that time, it is preferable to insert a cut line with the imposition portion pressed from above. At this time, since the film substrate 12 has already warped and the glass substrate 11 has also warped, if it is cut in a state where it is not pressed and fixed with any force, the surface is lifted sequentially from where the cut line enters. The part may be destroyed and the scriber may be damaged.

  As shown in FIG. 3C, after the empty cell in which the glass substrate 11 and the film substrate 12 are bonded together is completed, Δε is negative and Δn is about 0.1 in the gap between the glass substrate 11 and the film substrate 12. A liquid crystal material was injected by a vacuum injection method, and then the injection port was sealed with an ultraviolet curable resin. Thereafter, if necessary, the completed cell may be pressed with a pressing jig to perform in-plane uniformity.

  Thereafter, the glass substrate end face of the external extraction electrode terminal portion of the glass substrate 11 is chamfered, the cell is washed with a neutral detergent and dried, and then an in-plane retardation of 55 nm and a thickness direction retardation are formed outside the glass substrate 11. A polarizing plate integrated with a viewing angle compensation plate having negative biaxial optical anisotropy of 220 nm was bonded, and a polarizing plate was bonded to the outside of the film substrate 12. Finally, a lead frame was attached to the terminal portion to complete the liquid crystal display device 1 having the curved display surface 2. The polarizing plate used here is preferably as thin and flexible as possible so as to adapt to the bending state of the curved display surface 2.

  The operation at the time of front observation of the liquid crystal display device 1 was confirmed by connecting to a drive circuit via a lead frame, but it was confirmed that a good display state was obtained on both sides as in the conventional liquid crystal display device using a glass substrate. confirmed. Further, the completed liquid crystal display element is made of a flexible material and can maintain a curved surface state with a radius of curvature of about 1000 mm without applying an external force.

(Example 2)
It is also preferable to configure the liquid crystal display device using two sealing materials having different firing temperatures instead of the sealing material 14 in the first embodiment. Hereinafter, this case will be described in detail. In addition, about the content which overlaps with Example 1, after using a common code | symbol in a figure, those detailed description is abbreviate | omitted.

  The process is the same as in Example 1 described above until the step of forming the sealing material 14. Thereafter, as shown in FIG. 6A, a low-temperature firing seal material 14b in which 2 wt% of silica particles having a particle size of 3.2 μm are mixed on one surface of the mother glass substrate 111 is dispensed in a substantially annular shape (frame shape). Was applied. The sealing material 14b was formed inward by 1 mm from the in-plane region outer shape frame where the glass substrate 11 and the film substrate 12 overlap. Further, a high-temperature fired sealing material 14a similar to the sealing material 14 used in Example 1 was applied in a substantially annular shape by a dispenser. The sealing material 14a was formed inward by 2 mm from the in-plane region outer shape frame where the glass substrate 11 and the film substrate 12 overlap. Similar to Example 1, in the conductive pad portion for conducting between the glass substrate 11 and the film substrate 12, 2 wt% of gold-coated plastic particles having a particle size of 3.5 μm are mixed in addition to the silica particles. Moreover, the injection port was also provided similarly to Example 1.

  Next, the sealing material is fired. As shown in FIG. 6B, each substrate was first fixed in a flat state at a low temperature (70 ° C.), and then fired at a high temperature (150 ° C.) in a state of being removed from the jig. Thereby, since each substrate is stabilized in a curved state, it is considered that the load on the sealing material is reduced, which is more preferable. Subsequent steps were performed in the same manner as in Example 1, and a liquid crystal display device 1a provided with two sealing materials 14a and 14b as shown in FIG. 7 was completed.

  Thus, by double sealing using the low-temperature fired sealing material 14b and the high-temperature fired sealing material 14a, the film substrate 12 can be adhered to the glass substrate 11 without curling once by low-temperature firing. Thereafter, the film substrate 12 warps in the process of raising the temperature, and can be firmly fixed by the high-temperature fired sealing material 14a. Moreover, it is possible to avoid turning up the outer edge portion of the film substrate 12 by disposing the low-temperature fired sealing material 12b on the outside and bonding the portion first.

  In addition, this invention is not limited to the content of embodiment mentioned above and each Example, In the range of the summary of this invention, it can change and implement variously. For example, in the above description, a liquid crystal display device which is a liquid crystal device as an image display application has been illustrated, but the application is not limited to this, and the present invention can be applied to general liquid crystal devices.

DESCRIPTION OF SYMBOLS 11: Glass substrate 12: Film substrate 13: Columnar spacer 14, 14a, 14b: Sealing material 15, 16: Orientation film 17: Liquid crystal layer 21: Back side polarizing plate 22: Front side polarizing plate 111: Mother glass substrate 112: Mother film substrate 113: Support substrate 114: Dummy glass substrate 115: Cut line 116: Margin area 117: UV curable resin

Claims (5)

A method of manufacturing a liquid crystal device having a curved display surface,
(A) providing a plurality of spacers on one surface of a rigid substrate made of a flexible glass substrate ;
(B) forming a thermosetting sealing material in a substantially annular shape on one surface of the hard substrate;
(C) placing a film substrate made of a resin film having a property of shrinking in one direction when heat is applied, on one surface of the hard substrate with the sealing material interposed therebetween,
(D) have line heat treatment for curing the sealing material while the rigid substrate and the film substrate was pressed, deflect the film substrate and the hard substrate by using a shrinkage of the film substrate by the heat treatment in conjunction about,
(E) injecting a liquid crystal material into a gap between the hard substrate and the film substrate surrounded by the sealing material;
A method for manufacturing a liquid crystal device.   The overlapping region of the hard substrate and the film substrate has a length in the long side direction that is four times or longer than the length in the short side direction, and the direction in which the film substrate contracts corresponds to the long side direction. The method of manufacturing a liquid crystal device according to claim 1. (B) forms a first sealing material that cures at a relatively high temperature and a second sealing material that cures at a relatively low temperature;
3. The method of manufacturing a liquid crystal device according to claim 1, wherein (d) performs a relatively high temperature heat treatment after a relatively low temperature heat treatment. 4. The method of manufacturing a liquid crystal device according to claim 1 , wherein (d) is performed by arranging a dummy substrate outside the film substrate . A liquid crystal device having a curved display surface,
A hard substrate made of a flexible glass substrate ;
A film substrate made of a resin film having the property of shrinking in one direction when given a certain amount of heat,
A thermosetting sealing material that is provided in a substantially annular shape between each of the hard substrate and the one surface of the film substrate and fixes both;
A plurality of spacers disposed between each surface of the hard substrate and the film substrate;
A liquid crystal layer disposed between the hard substrate and the film substrate;
A liquid crystal device comprising:

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