JP2010217861A - Light scattering type liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light scattering type liquid crystal display device which does not cause exposure of a wiring electrode or poorly lighting up of part of the wiring electrode and can be manufactured with a simple manufacturing method. <P>SOLUTION: A first dummy electrode 7 having a gap is formed adjoining a display electrode 5 and the wiring electrode 6, an insulating film 8 is formed thereon, and a second dummy electrode 9 is formed thereon. The second dummy electrode 9 is formed so that the outer periphery of the display electrode 5 overlaps via the insulating film 8 and it further overlaps with the wiring electrode 6 and the first dummy electrode 7 via the insulating film 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light scattering liquid crystal display device, and more particularly to a liquid crystal display device using a polymer network liquid crystal.

  In recent years, a light scattering type liquid crystal display device has been studied as a display method that does not use a polarizing plate because of a demand for realizing a bright display. A typical example of the light scattering type liquid crystal display device is a polymer network type liquid crystal display device (hereinafter referred to as PN-LCD) using a polymer network liquid crystal (hereinafter referred to as PN-LC). PN-LC is a composite liquid crystal material in which a polymer resin that undergoes a cross-linking reaction by ultraviolet rays (UV) and is polymerized and a commonly used TN liquid crystal are mixed and dispersed. When UV-polymerizable polymer resin and TN liquid crystal are mixed in an appropriate composition and UV irradiation is performed, the polymer forms a network, and at the same time, the compounded TN liquid crystal is uniformly dispersed in the polymer network. As a result, the polymer and the TN liquid crystal have both properties.

  The PN-LCD is a light scattering type liquid crystal display element that scatters incident light by utilizing a difference in refractive index between a polymer network and a TN liquid crystal. Therefore, the polarizing plate used in the conventional TN liquid crystal display device is unnecessary. Furthermore, it is not necessary to form an alignment film for aligning liquid crystal molecules. Therefore, light loss is extremely small and bright display is possible. The PN-LCD can be provided at a low price because it only requires an ultraviolet irradiation device for curing the polymer dispersed liquid crystal, and does not require an alignment film accompanied by a high temperature treatment or an expensive polarizing plate. .

  FIG. 7 is a cross-sectional view of a PN-LCD in which PN-LC is sealed between two transparent substrates. A first transparent electrode 53 is formed on the surface of the lower first substrate 51 on the liquid crystal layer side, an insulating film layer 56 is formed thereon, a second transparent electrode 58 and a surrounding area are formed thereon. A peripheral electrode 60 is formed separately. The first transparent electrode 53 and the second transparent electrode 58 are connected through a contact hole 57 opened in the insulating film layer 56. A third transparent electrode 59 is formed on the entire surface of the opposing second substrate 52 on the liquid crystal layer side. The first substrate 51 and the second substrate 52 are bonded together with a gap provided through a sealing material 55, and PN-LC 54 is sealed in the gap (see, for example, Patent Document 1).

  PN-LC is in a light scattering state when no electric field is applied, and changes to a transmissive state when an electric field is applied. By applying a voltage between the first transparent electrode 53 and the third transparent electrode 59, an electric field is applied to the PN-LC 54 between the second transparent electrode 58 and the third transparent electrode 59. -LC 54 transmits incident light. The surrounding electrode 60 formed around the second transparent electrode 58 is set to the same potential as the third transparent electrode 59, for example. Thereby, the PN-LC 54 between the surrounding electrode 60 and the third transparent electrode 59 maintains a light scattering state. If the potential between the first transparent electrode 53 and the third transparent electrode 59 is set to the same potential, the PN-LC 54 returns from the light transmission state to the light scattering state. The peripheral electrode 60 is set to the same potential as the second transparent electrode 58. As a result, the PN-LC 54 between the surrounding electrode 60 and the third transparent electrode 59 maintains a light transmission state. The first transparent electrode 53 is formed below the insulating film layer 56. Therefore, if the wiring electrode is constituted by the first transparent electrode 53, it can intersect with the second transparent electrode for image formation formed in another region. That is, a more complicated pattern for image formation can be configured.

  However, a gap is formed between the second transparent electrode 58 in contact with the PN-LC 54 and the surrounding electrode 60. Since the light incident on the gap region is scattered, the gap can be visually recognized when the surrounding electrode 60 and the second transparent electrode 58 are in a light transmitting state.

  FIG. 8 is a cross-sectional view of a PN-LCD in which the above-described defect in which the gap can be seen is improved. PN-LC is sealed in the gap between the two glass substrates 61 and 62. On the liquid crystal layer side of the glass substrate 61, a marker display electrode pattern 63a and a wiring electrode pattern 63b connected thereto are formed. An insulating layer 64 and a peripheral electrode pattern 65 are laminated on the end portion of the sign display electrode pattern 63a. An insulating layer 64 and a peripheral electrode pattern 65 are also laminated on the wiring electrode pattern 63b. A similar electrode pattern is also formed on the surface of the glass substrate 62 on the liquid crystal layer side, and is placed facing the glass substrate 61. A sign is displayed by applying a voltage between the sign patterns 63a and 66a (see, for example, Patent Document 2). Since the wiring electrode patterns 63b and 66b are electrically shielded by the peripheral electrode patterns 65 and 68, respectively, the regions of the wiring electrode patterns 63b and 66b are not displayed. That is, the sign display is performed in the area 70B, and the area 70A is configured as a non-display area. In addition, since no gap is formed between the peripheral electrode pattern 65 (68) and the marker display electrode pattern 63a (66a), the boundary is not observed.

Japanese Patent Laid-Open No. 2001-125086 JP 2007-133088 PR

  In the PN-LCD shown in FIG. 7, since a gap is formed between the second transparent electrode 58 in contact with the PN-LC 54 and the peripheral electrode 60, the light incident on the gap area in the light transmission state. Will be scattered and gaps will be visible. Further, the first transparent electrode 53 that is a wiring electrode intersects with the gap region between the second transparent electrode 58 and the surrounding electrode 60 via the insulating film layer 56. Therefore, if a voltage is applied to the first transparent electrode 53 in order to light the PN-LC 54 on the second transparent electrode 58, the insulating film layer is also applied to the PN-LC 54 above the gap at the intersection. An electric field whose voltage has dropped by 56 is applied, and the light is half lit. As a result, there arises a problem that a non-uniform display or a gap between areas that should not be displayed is lit half. In order to prevent this, the insulating film layer 56 may be thickened. However, in that case, it takes a long time to deposit the insulating film layer 56, and a process for attaching the thick insulating film layer 56 is required. In addition, the manufacturing cost is increased due to, for example, a longer time for forming the contact hole 57.

  In the PN-LCD of FIG. 8, the peripheral electrode patterns 65 and 68 and the indicator display electrode patterns 63a and 66a are formed without a gap in the normal direction of the substrate surface. However, it is extremely difficult to form so as to eliminate the gap between the electrodes. A highly accurate mask alignment process and a highly accurate etching technique are required to make the tip portions of the sign display electrode patterns 63a and 66a coincide with the ends of the peripheral electrode patterns 65 and 68. Therefore, it is inevitable that the manufacturing apparatus is expensive and expensive.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a light scattering type liquid crystal display device with a relatively simple electrode configuration, which prevents display quality from being deteriorated due to visible gaps between the electrodes.

  The liquid crystal display device according to the present invention is a light scattering type liquid crystal display device in which a light scattering type liquid crystal is sandwiched between a pair of transparent substrates. A display electrode, a wiring electrode connected to the display electrode, and a first dummy electrode that is adjacent to and electrically separates the display electrode and the wiring electrode from each other and is electrically separated, and the outer periphery of the display electrode, the wiring electrode, An insulating film is formed on the first dummy electrode, and a second dummy electrode is formed on the insulating film so as to overlap the outer periphery of the display electrode, the wiring electrode, and the first dummy electrode, The counter electrode is formed on the display area on the inner surface of the other transparent substrate.

  In addition, the insulating film is formed over the entire upper surface of the display electrode, and the second dummy electrode is formed on the insulating film so as to overlap the outer periphery of the display electrode.

  In addition, a display electrode terminal electrically connected to the wiring electrode and a dummy terminal electrically connected to the first dummy electrode and the second dummy electrode were formed on the inner surface of the outer peripheral end of one transparent substrate. Here, the display electrode terminal has a laminated structure of an extended portion of the wiring electrode and a conductive film formed simultaneously with the second dummy electrode on the wiring electrode, and the dummy terminal extends from the first dummy electrode. The extending portion of the second dummy electrode is laminated on the portion.

  A liquid crystal display device manufacturing method according to the present invention is a light scattering liquid crystal display device manufacturing method in which a light scattering liquid crystal is sandwiched between a pair of transparent substrates, and a first transparent conductive film is deposited on the surface of one transparent substrate. And a first electrode pattern forming step for separating the first transparent electrode into a display electrode and a wiring electrode connected to the display electrode and a first dummy electrode adjacent to the display electrode and the wiring electrode through a gap, A resist film is formed on the surface of the transparent substrate, and the resist film is patterned so that the end surface has a reverse taper. The display terminal region constituted by the extended portion of the wiring electrode and the extended first dummy electrode A resist film forming step for leaving a resist film in a dummy terminal region constituted by a portion, an insulating film deposition step for depositing an insulating film on the surface of the transparent substrate on which the resist film is left, and a resist for removing the resist film A second transparent conductive film is deposited on the surface of the transparent substrate on which the insulating film is formed, and the second transparent conductive film is placed on the outer periphery of the display electrode, on the wiring electrode, and on the first dummy electrode. The second electrode pattern forming step for removing the outer peripheral portion from the display electrode except for the outer periphery, the step of depositing the third transparent conductive film on the surface of the other transparent substrate, and the electrode for one transparent substrate are formed. And a liquid crystal cell assembling step in which a gap is provided so as to be opposed to the surface on which the electrode of the other transparent substrate is formed and the light scattering type liquid crystal is sealed in the gap.

  Further, in a method of manufacturing a light scattering liquid crystal display device in which a light scattering liquid crystal is sandwiched between a pair of transparent substrates, a first transparent conductive film is deposited on the surface of one transparent substrate, and a first transparent electrode is displayed. A first electrode pattern forming step for separating the wiring electrode connected to the electrode and the display electrode and the first dummy electrode adjacent to the display electrode and the wiring electrode through a gap; and a resist film on the surface of one transparent substrate The resist film is formed and patterned so that the end face is reversely tapered, and the resist film is constituted by the display terminal region constituted by the extended portion of the wiring electrode and the extended portion of the first dummy electrode. A resist film forming step for leaving the dummy terminal region, a film deposition step for continuously depositing an insulating film and a second transparent conductive film on the surface of the transparent substrate on which the resist film is left, and a second transparent conductive film , The outer periphery of the display electrode A second electrode pattern forming step for removing the resist film from the top of the display electrode except for the outer peripheral portion, a resist film removing step for removing the resist film, The step of depositing the third transparent conductive film on the surface of the transparent substrate, the surface on which the electrode of one transparent substrate is formed, and the surface on which the electrode of the other transparent substrate is formed are provided with a gap and bonded together And a liquid crystal cell assembling step for enclosing the light scattering type liquid crystal in the gap.

  In the liquid crystal display device according to the present invention, a first dummy electrode is formed in the vicinity of the display electrode and the wiring electrode with a gap, an insulating film is formed thereon, and a second dummy electrode is formed thereon. . The second dummy electrode was formed so as to overlap the outer peripheral portion of the display electrode via the insulating film, and further overlapped with the wiring electrode and the first dummy electrode via the insulating film. Thus, no gap is generated between the display electrode and the first dummy electrode. Further, since all the wiring electrodes are covered with the first dummy electrode, an electric field from the wiring electrode is not applied to the light scattering type liquid crystal in the region where the wiring electrode is formed, and there is no region where the light scattering concentration is different. Furthermore, since it is not necessary to match the end portion of the display electrode with the end portion of the first dummy electrode, high-level mask alignment and high-level etching processing are not required. Therefore, the manufacturing method is simplified and the manufacturing cost can be reduced.

It is a typical longitudinal section of PN-LCD concerning the example of the present invention. It is a schematic diagram showing PN-LCD which concerns on the Example of this invention. It is a schematic diagram showing PN-LCD which concerns on the Example of this invention. It is a schematic diagram showing the manufacturing method of PN-LCD which concerns on the Example of this invention. It is a schematic diagram showing the manufacturing method of PN-LCD which concerns on the Example of this invention. It is a figure for demonstrating the dummy terminal part of PN-LCD which concerns on the Example of this invention. It is a cross-sectional schematic diagram of conventionally well-known PN-LCD. It is a cross-sectional schematic diagram of conventionally well-known PN-LCD.

  Hereinafter, a light scattering type liquid crystal display device according to the present invention will be described with reference to the drawings. Here, a PN-LCD using a polymer network liquid crystal as a light scattering type liquid crystal will be described. FIG. 1 is a longitudinal sectional view schematically showing a part of the display area DA of the PN-LCD 1. A PN-LC 4 is sandwiched between the upper transparent substrate 2 and the lower transparent substrate 3. On the surface of the lower transparent substrate 3 on the liquid crystal layer side, a display electrode 5, a wiring electrode 6 connected to the display electrode 5, and a first electrode that is electrically separated from the display electrode 5 with a space therebetween. A dummy electrode 7 is formed. An insulating film 8 is formed on the display electrode 5, the wiring electrode 6 and the first dummy electrode 7. A second dummy electrode 9 is formed on the insulating film 8 so as to overlap the outer peripheral portion of the display electrode 5, the wiring electrode 6, and the first dummy electrode 7. A translucent counter electrode 10 is formed on the surface of the upper transparent substrate 2 on the liquid crystal layer side. The display electrode 5 and the second dummy electrode 9 are overlapped with each other with an overlap width δ through the insulating film 8.

  The PN-LCD 1 operates as follows. A voltage is applied between the display electrode 5 and the counter electrode 10 via the wiring electrode 6 so that the second dummy electrode 9 has the same potential as the counter electrode 10. Then, an electric field is applied to the PN-LC 4 partitioned by the end of the second dummy electrode 9 on the display electrode 5, and the light scattering state is changed to the light transmitting state. Since no electric field is applied to the PN-LC 4 above the second dummy electrode 9, the light scattering state is maintained. By setting the display electrode 5 to the same potential as the counter electrode 10, the PN-LC 4 can be returned from the light transmitting state to the light scattering state.

  As another driving method, a voltage is applied between the second dummy electrode 9 and the counter electrode 10, and the display electrode 5 is set to the same potential as the counter electrode 10 through the wiring electrode 6. As a result, the PN-LC 4 on the second dummy electrode 9 changes to a light transmission state, and no electric field is applied to the PN-LC 4 on the display electrode 5, and the light scattering state is maintained. Therefore, the light scattering state can be displayed on the background of the light transmitting state. Although the insulating film 8 is formed on the display electrode 5, the voltage drop due to the insulating film 8 can be reduced by forming the insulating film 8 relatively thin. Further, as with the second dummy electrode 9, the insulating film 8 on the display electrode 5 may be removed.

  According to such a configuration of the PN-LCD 1, when the PN-LCD 1 is viewed from above, there is no gap between the display electrode 5 and the second dummy electrode 9, and the wiring electrode 6 is second in the display area DA. Covered by the dummy electrode 9. Accordingly, the PN-LC 4 above the wiring electrode 6 is not half-lit. If the first dummy electrode 7 and the display electrode 5 are simultaneously formed of a transparent conductive film and the second dummy electrode 9 is a transparent conductive film made of the same material, the boundary between the display electrode 5 and the lower transparent substrate 3 The light reflectance and the light reflectance at the boundary between the first dummy electrode 7 and the lower transparent substrate 3 are the same. Further, since the gap between the display electrode 5 and the first dummy electrode 7 is covered with the second dummy electrode 9 made of the same material as the display electrode 5 and the first dummy electrode 7, the display electrode 5 can be seen when it is lit or not lit. Or a gap between the display electrode 5 and the first dummy electrode 7 is not seen.

  Here, in PN-LC4, a polymer network is formed by mixing UV polymerizable polymer resin and TN liquid crystal and irradiating with UV light. The particle size of the polymer network was larger than the visible light wavelength and was approximately 1 μm. The liquid crystal layer thickness by PN-LC4 was set to several μm to several tens of μm. The thickness of the liquid crystal layer is preferably about 10 μm. Further, as the first dummy electrode 7, the display electrode 5, the wiring electrode 6, the second dummy electrode 9, and the counter electrode 10, transparent electrodes such as ITO (indium tin oxide), tin oxide, and zinc oxide can be used. . As the insulating film 8, a silicon dioxide film, a silicon oxide film, a silicon nitride film, or other metal oxide can be used. The overlap width δ between the display electrode 5 and the end of the second dummy electrode 9 may be set larger than the alignment accuracy of the second dummy electrode 9 with respect to the pattern of the display electrode 5. Further, the display electrode 5, the first dummy electrode 7, the insulating film 8, and the second dummy electrode 9 are formed on the liquid crystal layer side of the upper transparent substrate 2, and the counter electrode 10 is formed on the liquid crystal layer side of the lower transparent substrate 3. Also good.

  FIG. 2 is a diagram for explaining the PN-LCD 1 according to the present embodiment, and FIG. 3 is a diagram for explaining an electrode configuration. 2A is a schematic top view of the lower transparent substrate 3, FIG. 2B is a longitudinal sectional view of the XX ′ portion of the lower transparent substrate 3, and FIG. -It is a typical longitudinal section of LCD1. FIG. 3A is a schematic plan view of the first dummy electrode 7, the display electrode 5 and the wiring electrode 6, and FIG. 3B is a schematic plan view of the second dummy electrode 9.

  The electrode configuration on the lower transparent substrate 3 will be described with reference to FIGS. 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b). As shown in FIGS. 2A and 2B, the display electrode 5, the wiring electrode 6, and the first dummy electrode 7 are formed in the display area DA on the surface of the lower transparent substrate 3, and the insulating film 8 is formed thereon. And a second dummy electrode 9 is formed thereon. In addition, display terminals 11 and dummy terminals 12 are formed in the electrode terminal formation region of the lower transparent substrate 3.

  As shown in FIGS. 2A and 3A, the surface of the lower transparent substrate 3 has rectangular display electrodes 5a, 5b, 5c, and 5d, a circular display electrode 5e, and two arcuate shapes. Display electrodes 5f and 5g are formed. The wiring electrode 6a is connected to the display electrode 5a, is extended to the right side end portion of the lower transparent substrate 3, and constitutes the display terminal 11a at the end portion. The wiring electrode 6b is connected to the display electrode 5b, extends to the right side end of the lower transparent substrate 3, and constitutes the display terminal 11a at the end. Similarly, the other wiring electrodes 6c to 6g are connected to the display electrodes 5c to 5g, respectively, and are extended to the end of the right side to constitute the display terminal 11a.

  A first dummy electrode 7 is formed on the surface of the lower transparent substrate 3. The first dummy electrode 7 is adjacent to the display electrodes 5a to 5g and the wiring electrodes 6a to 6g with a gap therebetween, and is formed on the entire surface of the display area DA where the display electrode 5 is not formed. The first dummy electrode 7 extends to the right side end portion of the lower transparent substrate 3, and constitutes a dummy terminal 12a at the end portion.

  The gap between the display electrode 5 and the wiring electrode 6 and the first dummy electrode 7 is preferably several μm to several tens μm. In the PN-LCD 1 of the present embodiment, the area of the gap between the display electrode 5 and the wiring electrode 6 and the first dummy electrode 7 has an inconspicuous structure, but by narrowing the gap, It becomes difficult to see. The display electrode 5, the wiring electrode 6, and the first dummy electrode 7 can be formed simultaneously as transparent conductive films.

  The insulating film 8 is formed on the entire display area DA of the display electrode 5, the wiring electrode 6, and the first dummy electrode 7. The insulating film 8 is removed from the region where the display terminal 11a and the dummy terminal 12a are formed. At the end of the lower transparent substrate 3, counter electrode terminals 23a and 23b for connecting to the counter electrode 10 are formed.

  The configuration of the second dummy electrode 9 will be described with reference to FIGS. 2B and 3B. In the display area DA of the second dummy electrode 9, openings 18a to 18g are formed corresponding to the display electrodes 5a to 5g. The ends of the openings 18a to 18g of the second dummy electrode 9 are formed so as to overlap with the outer peripheral portions of the display electrodes 5a to 5g with an overlap width δ. With this configuration, there is no gap between the display unit and the non-display unit. The overlap width δ may be set larger than the alignment accuracy of the second dummy electrode 9 with respect to the display electrode 5. The second dummy electrode 9 extends above the dummy terminal 12a formed at the right end of the lower transparent substrate 3 and constitutes a dummy terminal 12b. Since the dummy terminals 12b are directly stacked on the dummy terminals 12a, they are electrically connected to each other. A plurality of display terminals 11 b are formed separately from each other at the right side end of the lower transparent substrate 3. The display terminal 11b is formed to be electrically separated from the dummy terminal 12b and the second dummy electrode 9. The second dummy electrode 9 and the display terminal 11b can be formed simultaneously.

  As shown in FIG. 2C, the PN-LCD 1 includes a lower transparent substrate 3 having the above-described configuration, and an upper transparent substrate 2 having a counter electrode 10 made of a transparent conductive film on the liquid crystal side surface. It is pasted through. The gap is filled with PN-LC4. By applying a voltage between the display electrodes 5f, 5e, and 5g and the counter electrode 10, an electric field is applied to the PN-LC 4 therebetween, and the light scattering state is changed to the light transmission state. As described above, the PN-LCD 1 performs the display operation by switching between the light scattering state and the light transmission state, so that it is not necessary to use a polarizing plate.

  When a silicon dioxide film is used as the insulating film 8 and is formed over the entire upper surface of the display electrode 5 as shown in FIG. 2B, the thickness of the insulating film 8 is preferably 30 nm to 160 nm. More preferably, it is about 40 to 80 nm. If the silicon dioxide film is 30 nm or less, dielectric breakdown or short circuit is likely to occur between the display electrode 5 or the wiring electrode 6 and the second dummy electrode 9. If the silicon dioxide film is 160 nm or more, the insulation film 8 on the display electrode 5 This is because the voltage drop becomes large. Further, when the silicon dioxide film is 40 nm or less, it is likely to be colored due to light interference.

  Moreover, the pattern of the display electrode 5 can be made into a free shape such as a character, a symbol, or a symbol mark as necessary. In addition to the display terminals 11 and the dummy terminals 12, in the electrode terminal formation region of the lower transparent substrate 3, a counter terminal electrically connected to the counter electrode 10 of the upper transparent substrate 2 is formed, and the electrode of the terminal portion is formed. It can be configured intensively.

  Next, a basic configuration of the manufacturing method of the PN-LCD 1 will be described with reference to FIGS. First, the first transparent conductive film 15 is deposited on the surface of one transparent substrate. Next, through the patterning process, the first transparent conductive film 15 is connected to the display electrode 5, the wiring electrode 6 connected to the display electrode 5, and the display electrode 5 and the wiring electrode 6 adjacent to each other with a gap. Separated into one dummy electrode 7. A display terminal 11 is formed at the end of the wiring electrode 6, and a dummy terminal 12 is formed at the end of the first dummy electrode 7.

  Next, a resist film 16 is applied to the surface of the substrate. Then, the resist film 16 is left in the region of the display terminal 11 and the dummy terminal 12 so that the cross section has an inverse taper. Next, the insulating film 8 is deposited on the surface where the resist film 16 is left. Next, a second transparent conductive film 17 is deposited on the surface on which the insulating film 8 is deposited. Next, the resist film is removed, and the insulating film 8 is patterned by a lift-off method. The resist film is easy to be removed because the end section has an inverse taper. Next, a second transparent conductive film 17 is deposited, and the second transparent conductive film 17 is left on the outer peripheral portion of the display electrode, on the wiring electrode, and on the first dummy electrode, except for the outer peripheral portion. , Removed from above the display electrode. The patterned second transparent conductive film 17 is used as the second dummy electrode 9.

  Also, a third transparent conductive film is provided on the surface of the other transparent substrate to form the counter electrode 10. Next, the surface on which the electrode of one transparent substrate is formed and the surface on which the electrode of the other transparent substrate is formed are bonded with a gap, and the PN-LC 4 is sandwiched in this gap to complete.

  In this way, the overlapping width between the outer peripheral portion of the display electrode 5 and the second dummy electrode 9 can be set according to the alignment accuracy of the manufacturing process. If the alignment accuracy of the manufacturing process is low, the overlap width δ between the outer periphery of the display electrode 5 and the second dummy electrode 9 may be set large. If the alignment accuracy is high, the overlap width δ Can be set small. Therefore, a PN-LCD with good display quality can be manufactured with a simple manufacturing apparatus.

  Next, the manufacturing method of the PN-LCD 1 of this embodiment will be specifically described with reference to FIG. FIG. 4A is a schematic diagram of a substrate cross section showing a state in which the first transparent conductive film 15 is formed on the surface of the lower transparent substrate 3. For the first transparent conductive film 15, ITO, tin oxide, zinc oxide or the like can be used. The first transparent conductive film 15 is deposited from 10 nm to 400 nm by a sputtering method or a vapor deposition method. Preferably, it is deposited to a thickness of 30 nm to 200 nm.

  FIG. 4B is a schematic view of a substrate cross section showing a state in which the first transparent conductive film 15 is patterned. A resist film is applied on the first transparent conductive film 15, and the first transparent conductive film 15 is patterned through a photolithography process and an etching process to form the display electrode 5, the first dummy electrode 7, the wiring electrode 6, and the display terminal 11a. To separate. The display terminal 11 a is an extension part of the wiring electrode 6. Although not shown, a dummy terminal 12 that is an extended portion of the first dummy electrode 7 is formed close to the display terminal 11a.

  FIG. 4C is a schematic view of a substrate cross section showing a state in which the resist film 16 is patterned. A resist film 16 is applied on the lower transparent substrate 3 on which the display electrodes 5 and the like are formed using a spinner or the like. Next, the resist film 16 is left on the display terminal 11a so that the end section has an inverse taper. Although the resist film 16 is left at the other end of the lower transparent substrate 3, it is not always necessary to leave it.

  FIG. 4D is a schematic diagram of a substrate cross section showing a state in which the insulating film 8 is deposited. An insulating film 8 is deposited on the lower transparent substrate 3 where the resist film 16 is left. Silicon dioxide is deposited by several 10 nm to several 100 nm by sputtering. The silicon dioxide film is deposited on the upper surface of the resist film 16, the electrode surface such as the display electrode 5, and the surface of the lower transparent substrate 3. Instead of the silicon dioxide film, a silicon oxide film, a silicon nitride film, or other metal oxide film can be used as the insulating film 8.

  FIG. 4E is a schematic diagram of a substrate cross section showing a state in which the second transparent conductive film 17 is deposited after the resist film 16 is removed. By removing the resist film 16, the surfaces of the display terminals 11a and the dummy terminals 12a (not shown) are exposed. Since the end portion of the resist film 16 has a reverse taper shape, the insulating film 8 deposited on the resist film 16 and the insulating film 8 deposited on the wiring electrode 6 are separated. Therefore, the resist film 16 can be easily peeled off. A second transparent conductive film 17 made of ITO is deposited on this surface by sputtering or vapor deposition. The film thickness and sheet resistance of the first transparent conductive film can be arbitrarily selected similarly to the first transparent conductive film. Moreover, it can replace with ITO and can use transparent conductive materials, such as a tin oxide, an indium oxide, and a zinc oxide.

  FIG. 4F is a schematic diagram of a substrate cross section showing a state in which the second transparent conductive film 17 is patterned. The outer periphery of the display electrode 5 is left, and the second transparent conductive film 17 inside the display electrode 5 is removed to form the second dummy electrode 9. Further, it is separated from the second dummy electrode 9 and left on the display terminal 11a to form a display terminal 11b as a conductive film. Thereby, the dummy terminal 12a and the dummy terminal 12b are electrically connected. The dummy terminal 12a (not shown) is left above the second dummy electrode 9 so as to be electrically connected. Thereby, the dummy terminal 12a and the dummy terminal 12b are electrically connected.

  The overlapping width between the outer periphery of the display electrode 5 and the second dummy electrode 9 can be set according to the alignment accuracy of the manufacturing process. If the alignment accuracy of the manufacturing process is low, the overlap width δ between the outer periphery of the display electrode 5 and the second dummy electrode 9 may be set large. If the alignment accuracy is high, the overlap width δ Can be set small. In addition, a second dummy electrode 9 is always provided between the display electrode 5 and the first dummy electrode 7 with an insulating film 8 interposed therebetween. Thereby, it is possible to make the gap between the display electrode 5 and the first dummy electrode 7 difficult to see.

  FIG. 4G is a schematic longitudinal sectional view showing a state where the liquid crystal panel is assembled. The upper transparent substrate 2 on which the counter electrode 10 made of a transparent electrode is formed and the lower transparent substrate 3 are bonded together via a seal portion 14. The thickness of the liquid crystal layer is several μm to several tens of μm. The gap between the substrates is filled with liquid crystal in which UV polymerizable polymer resin and TN liquid crystal are mixed and dispersed. This liquid crystal panel is irradiated with ultraviolet rays using a metal halide lamp or a mercury lamp. As a result, a polymer network of approximately 1 μm is generated and designated as PN-LC4.

  A manufacturing method of the PN-LCD 1 of the present embodiment will be described with reference to FIG. In this embodiment, the process up to the patterning process of the display electrode 5, the wiring electrode 6, and the first dummy electrode 7 is the same as the manufacturing method of the embodiment 2 shown in FIGS. .

  FIG. 5A is a schematic diagram of a substrate cross section showing a state in which the resist film 16 is patterned. A resist film 16 is applied on the lower transparent substrate 3 on which the display electrodes 5 and the like are formed using a spinner or the like. Next, the resist film 16 is left on the left end portion of the lower transparent substrate 3 and the dummy terminal 12a so that the end section has an inverse taper. The resist film 16 left on the dummy terminals 12a is formed so as to occupy a smaller area than the planar shape on which the dummy terminals 12 (see FIG. 2) are formed.

  FIG. 5B is a schematic view of a substrate cross section showing a state in which the insulating film 8 and the second transparent conductive film 17 are deposited. The insulating film 8 and the second transparent conductive film 17 are continuously deposited. A silicon dioxide film or a silicon nitride film is deposited as the insulating film 8 by sputtering. ITO, tin oxide, zinc oxide or the like is deposited as the second transparent conductive film 17 by sputtering or vapor deposition. Since the end section of the resist film 16 has an inversely tapered shape, the deposited film on the resist film 16 and the deposited film on the dummy terminal 12a are separated. Therefore, the resist film 16 can be easily peeled off in the next lift-off process.

  FIG. 5C is a schematic view of a substrate cross section showing a state in which the resist film 16 has been removed. The surface of the central portion of the dummy terminal 12a is exposed. Similarly, the surface of the display terminal 11 (not shown) is exposed. FIG. 5D is a schematic view of a cross section of the substrate obtained by patterning and removing the second transparent conductive film 17 on the display electrode 5. The second transparent conductive film 17 is patterned through a lithography process and an etching process to form a second dummy electrode 9 and a dummy terminal 12b composed of an extended portion of the second dummy electrode 9. The second dummy electrode 9 is left on the outer periphery of the display electrode 5, on the wiring electrode 6 and on the first dummy electrode 7, and is removed from the display electrode 5 except for the outer periphery.

  FIG. 6 is an enlarged view for explaining the region of the dummy terminal 12. 6 (a) is a schematic top view of the dummy terminal 12, FIG. 6 (b) is a schematic vertical cross-sectional view thereof, and FIG. 6 (c) is a bonded flexible substrate 20 for connection to an external circuit. It is a cross-sectional schematic diagram showing a state. As shown in FIG. 6A, an opening from which the resist film 16 is removed is formed at the center of the dummy terminal 12b, which is an extension of the second dummy electrode 9, and the dummy terminal 12a is exposed. . As can be understood from the cross section shown in FIG. 6B, the dummy terminal 12 a and the dummy terminal 12 b are electrically separated through the insulating film 8. However, as shown in FIG. 6B, the dummy terminal 12a and the dummy terminal 12b can be electrically connected by crimping the flexible substrate 20 via the conductive material 21 of the anisotropic conductive film 22. it can. Thereby, the first dummy electrode 7 and the second dummy electrode 9 are electrically connected.

  Next, FIG. 5E is a schematic longitudinal sectional view of the liquid crystal panel showing a state assembled to the liquid crystal panel. This is the same as FIG. 4G, and the description is omitted.

  By forming in this way, the patterning process is less than once compared with the manufacturing method in Example 2. Therefore, the manufacturing cost can be reduced. Similarly to the second embodiment, the size of the resist film 16 formed on the display electrode 5 may be set according to the alignment accuracy of the manufacturing process. That is, when the alignment accuracy of the manufacturing process is low, the resist film 16 is set to remain inside the outer peripheral portion of the display electrode 5, and when the alignment accuracy is high, the resist film 16 is set on the outer peripheral portion of the display electrode 5. The resist film 16 may be left close to each other.

  In each of the above-described embodiments, the first dummy electrode 7 shown in FIG. 1 is formed. Moreover, although the inorganic insulating film is illustrated as the insulating film 8, an organic insulating film can also be used.

1 PN-LCD
2 Upper transparent substrate 3 Lower transparent substrate 4 PN-LC
5 Display electrode 6 Wiring electrode 7 First dummy electrode 8 Insulating film 9 Second dummy electrode 10 Counter electrode 11 Display terminal 12 Dummy terminal 14 Seal portion

Claims (6)

In a light scattering type liquid crystal display device in which a light scattering type liquid crystal is sandwiched between a pair of transparent substrates,
The display area on the inner surface of one transparent substrate that is visible from the outside is adjacent to the display electrode, the wiring electrode connected to the display electrode, and the display electrode and the wiring electrode with a gap. A first dummy electrode that is electrically separated is formed;
An insulating film is formed on the outer periphery of the display electrode, the wiring electrode, and the first dummy electrode,
A second dummy electrode is formed on the insulating film so as to overlap the outer peripheral portion of the display electrode, the wiring electrode, and the first dummy electrode,
A light scattering type liquid crystal display device, wherein a counter electrode is formed in the display area on the inner surface of the other transparent substrate.   The insulating film is formed over the entire upper surface of the display electrode, and the second dummy electrode is formed on the insulating film so as to overlap an outer periphery of the display electrode. The light scattering type liquid crystal display device according to claim 1. A display electrode terminal electrically connected to the wiring electrode and a dummy terminal electrically connected to the first dummy electrode and the second dummy electrode are formed on the inner surface of the outer peripheral end of the one transparent substrate. Formed,
The display electrode terminal has a laminated structure of a conductive film formed simultaneously with the second dummy electrode on the extended portion of the wiring electrode,
3. The light scattering type according to claim 1, wherein the dummy terminal has a stacked structure in which the extended portion of the second dummy electrode is stacked on the extended portion of the first dummy electrode. Liquid crystal display device.   The light-scattering liquid crystal display device according to claim 1, wherein the insulating film is formed of an inorganic insulating film or an organic insulating film. In a method for manufacturing a light scattering liquid crystal display device in which a light scattering liquid crystal is sandwiched between a pair of transparent substrates,
A first transparent conductive film is deposited on the surface of one transparent substrate, and the first transparent electrode is brought close to the display electrode and the wiring electrode connected to the display electrode via the gap. A first electrode pattern forming step for separating the first dummy electrode;
A resist film is formed on the surface of the one transparent substrate, the resist film is patterned so that the end surface is reversely tapered, and a display terminal region constituted by an extended portion of the wiring electrode; A resist film forming step of leaving the resist film in a dummy terminal region constituted by the extended portion of the dummy electrode;
An insulating film deposition step of depositing an insulating film on the surface of the transparent substrate where the resist film is left;
A resist film removing step for removing the resist film;
A second transparent conductive film is deposited on the surface of the transparent substrate on which the insulating film is formed, and the second transparent conductive film is deposited on the outer periphery of the display electrode, on the wiring electrode, and on the first dummy electrode. A second electrode pattern forming step that is left on and removed from above the display electrode except for the outer peripheral portion;
Depositing a third transparent conductive film on the surface of the other transparent substrate;
A liquid crystal cell assembly in which a surface on which the electrode of the one transparent substrate is formed and a surface on which the electrode of the other transparent substrate is formed are provided with a gap therebetween and light scattering liquid crystal is sealed in the gap A process for producing a light-scattering liquid crystal display device. In a method for manufacturing a light scattering liquid crystal display device in which a polymer network liquid crystal is sandwiched between a pair of transparent substrates,
A first transparent conductive film is deposited on the surface of one transparent substrate, and the first transparent electrode is brought close to the display electrode and the wiring electrode connected to the display electrode via the gap. A first electrode pattern forming step for separating the first dummy electrode;
An area of a display terminal configured by forming a resist film on the surface of the one transparent substrate, patterning the resist film so that an end surface thereof is reversely tapered, and forming the resist film by an extended portion of the wiring electrode And a resist film forming step that remains in a dummy terminal region constituted by the extended portion of the first dummy electrode;
A film deposition step of continuously depositing an insulating film and a second transparent conductive film on the surface of the transparent substrate on which the resist film is left;
The second transparent conductive film is left on the outer periphery of the display electrode, on the wiring electrode, and on the first dummy electrode, and removed from the display electrode except for the outer periphery. An electrode pattern forming step;
A resist film removing step for removing the resist film;
Depositing a third transparent conductive film on the surface of the other transparent substrate;
A liquid crystal cell assembly in which a surface on which the electrode of the one transparent substrate is formed and a surface on which the electrode of the other transparent substrate is formed are provided with a gap therebetween and light scattering liquid crystal is sealed in the gap A process for producing a light-scattering liquid crystal display device.

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