JP4506231B2 - Color filter substrate for IPS liquid crystal display device and IPS liquid crystal display device using the same - Google Patents

Description

  The present invention relates to a color filter substrate for a liquid crystal display device that is suitably used for a liquid crystal display device that is widely used as a display medium for information terminals, and a liquid crystal display device using the color filter substrate. The present invention relates to a liquid crystal display device color filter excellent in cost and quality without impairing display characteristics, and a high quality liquid crystal display device obtained by using the same.

  In recent years, liquid crystal display devices have expanded the market base from large display devices for televisions and personal computers to small devices for portable information terminals based on the reliability of image display capability over many years. The characteristics required for liquid crystal display devices vary widely depending on the application, but in particular, small liquid crystal display devices typified by mobile phones, which have rapidly spread in recent years, require a display unit to be stored in a limited space. Minimizing the size of the display device was an important development factor.

  In a conventional liquid crystal display device, a liquid crystal panel is formed on a so-called TAB film in which a copper film is laminated on a polyimide film and a liquid crystal panel portion in which a color filter and an electrode substrate are sandwiched and sandwiched, and a copper wiring is laminated on a polyimide film It was comprised by the mounting circuit part connected to the part. This configuration has the disadvantage of increasing the size of the liquid crystal display device because it requires extra space in addition to the display portion, and considering the configuration of the liquid crystal display device that satisfies the downsizing of the display portion in conjunction with the popularization of small liquid crystal display devices It has been. One of them is a liquid crystal display device using an electrode substrate as a technique for forming polycrystalline silicon (see Non-Patent Document 1 and Non-Patent Document 2).

Further, amorphous silicon has been used so far as a thin film transistor (TFT) material formed as an electrode for driving a liquid crystal (or sometimes called a switching element) on an electrode substrate. Amorphous silicon is capable of heating an SiO ₂ layer at a relatively low temperature while exhibiting good electrical characteristics with little current leakage, so that an electrode can be easily formed on a glass substrate at a low cost. Compared to, the manufacturing cost was superior. However, since amorphous silicon has a low crystal continuity, the electron mobility (or sometimes referred to as field transfer effect) is small and the signal delay cannot be ignored. However, it is difficult to construct a complicated circuit, which is a factor that requires a circuit mounted outside the liquid crystal panel.

  On the other hand, polycrystalline silicon, which has higher crystallinity than amorphous silicon, has a high electron mobility, and a sufficient signal speed can be obtained even on a complicated circuit. Therefore, it becomes possible to form not only a liquid crystal driving electrode on the electrode substrate but also a liquid crystal driving circuit on the electrode substrate by using polycrystalline silicon as a material, and the liquid crystal display device can be included in the electrode substrate. It has become possible to achieve a significant reduction in size.

  Furthermore, until now, the manufacturing process of polycrystalline silicon has required a crystallization temperature of around 1,000 ° C., but now it is represented by a crystallization process combining a heat treatment of around 450 ° C. and a high energy laser beam. Low cost technology has been adopted, and it has been rapidly spreading as a suitable combination for small liquid crystal display devices. Currently, many liquid crystal display devices using polycrystalline silicon are driven to make the size as small as possible by taking advantage of their advantages. The circuit is arranged around the display area.

  In contrast, a color filter used in a liquid crystal display device using polycrystalline silicon forms a transparent protective film layer or a transparent electrode layer on a colored layer after forming at least a plurality of colored layers on a transparent substrate. Although the existing structure laminated on the upper layer is used, no consideration is given to electrical insulation for the liquid crystal driving circuit provided on the electrode substrate. That is, when a transparent electrode layer is laminated on the uppermost layer on the color filter substrate, the transparent electrode layer is generally formed up to a part of the non-display area from the viewpoint of securing the liquid crystal driving area. Yes, it is not possible to maintain sufficient insulation between the transparent electrode layer and the driving circuit when bonded to the electrode substrate with the liquid crystal driving circuit arranged in the non-display area. Even in the case where the films are laminated, it is a problem to prevent electrostatic breakdown of the driving circuit, which is estimated to be caused by polarization generated on the protective film due to the influence of the electromagnetic field generated from the liquid crystal driving circuit.

  In order to suppress electrical short-circuiting and electrostatic breakdown, it is necessary to uniformly maintain a minute gap between the color filter substrate and the electrode substrate. Conventionally, a method in which a spacer material having a substantially single shape such as ceramic beads or glass fiber is spread and bonded onto a substrate has been the mainstream. However, these spacer materials are simply sprayed, and depending on their distribution, the substrate gap becomes non-uniform, the gap near the drive electrode becomes extremely narrow, and an electrical short circuit occurs. In addition, in the display area, display light is scattered in the vicinity of the spacer material, which causes a problem of display performance deterioration such as display unevenness and defective bright spots. Therefore, at present, in order to solve the above-described problem, a configuration in which a columnar spacer made of at least a resin is fixed on a color filter substrate and the substrate gap is uniformly maintained (see Patent Document 1 and Patent Document 2).

  In the case of columnar spacers, there is an advantage that they can be fixed in a uniform distribution state and the scattering of display light is at least weaker than that of the spacer material. On the other hand, in order to obtain a predetermined substrate gap, the height of the columnar spacer is about 2 to 10 μm. It is necessary to provide as minute protrusions. However, in a liquid crystal display device in which a liquid crystal driving circuit is arranged in a non-display area on the electrode substrate, display defects may occur even if a sufficient gap is formed between the electrode substrate and the color filter by a columnar spacer. .

  About these causes, the present inventors analogized as follows. That is, the columnar spacer is crushed when the electrode substrate and the color filter substrate are bonded together depending on the arrangement condition, and the gap between the liquid crystal driving circuit and the color filter substrate is narrowed. Even if this change in the gap is such that a conventional liquid crystal display device cannot cause a display failure, charging is generated on the electrode substrate due to a polarization phenomenon generated by the drive circuit, and the discharge and static electricity between the color filter substrates are caused. The analogy was that the drive circuit would become abnormal due to electrical breakdown, resulting in poor display.

  Regarding the short circuit between the color filter substrate and the electrode substrate, the transparent electrode layer on the top of the columnar spacer is short-circuited with the opposite liquid crystal driving electrode in the color filter that is laminated in the order of at least the colored layer, the columnar spacer, and the transparent electrode layer. It is known. In order to prevent this type of defect, a method of removing the transparent electrode layer on the upper surface of the columnar spacer (see Patent Document 2, Patent Document 3 and Patent Document 4), an insulating film is formed on the columnar spacer, However, the removal of the transparent electrode layer and the formation of the insulating film have new problems such as an increase in cost and a decrease in yield due to an increase in the number of processes. Further, although it is an effective means for the liquid crystal driving electrode provided in the display area, the liquid crystal driving circuit provided in the non-display area having a size 10 times or more that of the driving electrode. However, this was not enough for the study.

  In addition, there is a proposal (see Patent Document 6) in which columnar spacers on the color filter substrate are formed by removing the driving electrode portion to protect the electrodes and prevent short circuits. In this method, since the space between the driving circuit and the transparent electrode layer on the color filter substrate is filled with air, it is possible to maintain a very high insulating property. If there is no holding, it is obvious that the surrounding gaps are non-uniform, which causes a problem in display quality.

  In addition, regarding the electrical short circuit between the transparent electrode layer on the color filter substrate and the pixel electrode on the electrode substrate, insulation is provided by forming an alignment film after forming a columnar spacer on the transparent electrode layer. There is a technology to hold (see Patent Document 7). However, as described in Patent Document 7, the drive voltage is low and the pixel electrode that performs a simple operation is effective for insulation, but is sufficient for a drive circuit that performs complex processing. It is hard to say that insulation is maintained.

  On the other hand, although it is different from the technique for the insulation holding technique, a technique for columnar spacer distribution inside and outside the display region is disclosed in order to prevent the columnar spacers from being crushed when the substrates are bonded (Patent Literature). 8 and Patent Document 9). The means for increasing the arrangement density outside the area with respect to the arrangement density of the columnar spacers in the display area is an effective means for an electrical short circuit that occurs due to an unnecessarily reduced substrate gap during bonding. However, the examination as an insulation holding technique is insufficient, and it is necessary to find a specific condition for holding electrical insulation between the liquid crystal driving circuit on the electrode substrate and the color filter substrate.

As described above, the insulation holding technology between the electrode substrate in which the liquid crystal driving circuit is provided outside the display area and the color filter substrate facing the driving circuit is still immature, and currently corresponds to, for example, the driving circuit. Removing the transparent electrode layer in the region is used as the simplest means for preventing a short circuit. Examples of the method for removing the transparent electrode layer include masking, etching, laser processing, and the like (see Patent Document 10). However, a fine processing technique in the vicinity of the display area is required, and depending on the method of removal, the driving circuit area may be removed. A display defect occurs due to a short circuit due to the remaining electrode or an electrode defect in the display region, resulting in a decrease in yield. In particular, liquid crystal display devices using polycrystalline silicon make use of the advantage that a drive circuit can be placed around the display area and strive to reduce the peripheral area as much as possible. This contributed to the need to invent the technology.
JP 60-217337 A Japanese Patent Laid-Open No. 11-344700 JP 2000-131701 A JP-A-10-282332 Japanese Patent Laid-Open No. 2001-249221 JP 2003-131701 A JP 2003-43497 A JP 2002-277865 A JP 2000-56314 A JP-A-8-234190 p. 5 “Journal of Liquid Crystal Society”, 2000 vol. 4 No. 2 p. 131 “Nikkei Microdevices separate volume flat panel display (practical)”, 2002, p. 102

  The object of the present invention is to provide a liquid crystal display device using polycrystalline silicon that can provide a liquid crystal driving circuit in a non-display area on an electrode substrate as a result of examination in view of the drawbacks of the prior art as described above. Focusing on the importance of technology to prevent electrical short circuit between the transparent electrode layer and transparent protective film layer laminated on the top layer of the filter substrate and the drive circuit, insulation can be maintained in a simple manner without impairing display characteristics Another object of the present invention is to provide a color filter substrate for a liquid crystal display device and a liquid crystal display device using various techniques.

  The technology for preventing an electrical short circuit between the liquid crystal driving circuit formed on the electrode substrate of the present invention and the color filter substrate has been solved by the following configuration.

That is, the color filter substrate of the present invention includes a liquid crystal layer sandwiched between electrode substrates, and the electrode substrate includes a display region in which liquid crystal driving electrodes are arranged in at least a predetermined pattern on the substrate and a liquid crystal driving circuit. The color filter substrate has a columnar spacer disposed on a display region provided with a plurality of colored regions at positions corresponding to the liquid crystal driving electrodes of the electrode substrate, and a periphery of the display region. the insulating layer possess position opposing to the liquid crystal driving circuit of the non-display region formed on the insulating layer and the volume resistance value of the volume resistivity of the columnar spacers is color filter substrate top layer and the same or larger, and an insulating IPS type color filter for a liquid crystal display device having a relative dielectric constant of the layer and the columnar spacer and wherein the dielectric constant and the same as or less of the color filter substrate top layer It is a plate.

The color filter for a liquid crystal display device of the present invention includes the following preferred embodiments .
(1) A color filter substrate for a liquid crystal display device, wherein the insulating layer is formed using the same material as the columnar spacer.
(2) A color filter substrate for a liquid crystal display device, wherein the insulating layer is formed in a rectangular parallelepiped shape having a trapezoidal cross-sectional area.
(3) The height hi of the insulating layer formed on the light shielding area of the non-display area from the bottom of the light shielding area, and the height hs of the columnar spacer formed on the light shielding area of the display area from the bottom of the light shielding area. A color filter substrate for a liquid crystal display device satisfying | hi-hs | ≦ 1.0 μm .

Furthermore, a high quality IPS liquid crystal display device can be manufactured using the color filter for IPS liquid crystal display device of the present invention.

In the color filter substrate for an IPS mode liquid crystal display device of the present invention, a columnar spacer and an insulating layer are formed, and electrical insulation from the liquid crystal driving circuit provided on the electrode substrate is achieved by using the above-described configuration. It is possible to provide a low-cost and high-quality color filter for an IPS liquid crystal display device with respect to a liquid crystal display device that can be easily held and has a liquid crystal driving circuit and a miniaturized size. .

  Hereinafter, the color filter and the liquid crystal display device of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a schematic cross-sectional view of a color filter substrate for a liquid crystal display device provided with columnar spacers and an insulating layer of the present invention, and FIG. 2 is a schematic front view of the color filter substrate for a liquid crystal display device of FIG.

  In the color filter substrate for a liquid crystal display device according to the present invention shown in FIGS. 1 and 2, a display region R in which liquid crystal driving electrodes 2 are arranged in at least a predetermined pattern on the substrate 1 and a liquid crystal driving signal are supplied to the liquid crystal driving electrode 2. There is a non-display region UR in which a liquid crystal driving circuit 3 is provided for providing an electrode substrate D having an insulating film 4 provided on the liquid crystal driving electrode 2 and the liquid crystal driving circuit 3. In contrast, on the other substrate 1 ′, a light shielding layer 5 ′ is provided in the non-display area UR and a light shielding layer 5 that divides a predetermined pattern of the liquid crystal driving electrodes 2 arranged in the display area R of the electrode substrate D, A color filter substrate C in which a plurality of colored regions 6 (6R, 6G, 6B) are arranged on the predetermined pattern and a transparent electrode layer 8 is laminated on the colored regions 6 with a transparent protective film 7 interposed therebetween is a liquid crystal layer. 11 is arranged so as to hold it. A columnar spacer 9 made of at least a resin is disposed on the transparent electrode layer 8 in the display region R, and a liquid crystal driving circuit on the electrode substrate D is disposed on the transparent electrode layer 8 in the non-display region UR. An insulating layer 10 is disposed in the liquid crystal driving circuit region 3 ′ opposite to the liquid crystal driving circuit 3. In FIG. 2, the insulating layer 10 formed on the liquid crystal driving circuit 3 on the electrode substrate D and the liquid crystal driving circuit region 3 ′ on the color filter substrate C are both embedded in the liquid crystal layer 11. However, it may be formed in a non-display area outside the liquid crystal layer.

  The color filter substrate for a liquid crystal display device shown in FIG. 3 to FIG. 5 is another embodiment of the present invention, and the uppermost layer of the color filter substrate provided with the columnar spacer and the insulating layer of FIG. The basic structure other than this is the same as the color filter substrate for a liquid crystal display device shown in FIG. The basic front view of FIG. 4 is the same as the color filter substrate for the liquid crystal display device of FIG. 2 except that the insulating layer is formed around the non-display area UR. Further, the color filter substrate of FIG. 5 has a different laminated structure of the insulating layer arranged in the non-display area UR of FIG. 1 except that the lower layer is formed using the same material as the colored area under the insulating layer. The basic structure is the same as the color filter substrate for a liquid crystal display device of FIG.

  In the present invention, the substrates 1 and 1 ′ used for the electrode substrate D and the color filter substrate C are, for example, inorganic glasses such as quartz glass, borosilicate glass, aluminosilicate glass, and soda lime glass whose surface is coated with silica. A transparent substrate such as a plastic film or sheet is preferably used.

  For the light shielding layers 5 and 5 ′ provided on the substrate 1 ′ of the color filter substrate C, a metal light shielding layer made of a metal film such as chromium or nickel, a metal oxide film, a metal oxynitride film, or a laminated film thereof is used. Further, the light shielding layers 5 and 5 ′ may be resin light shielding layers made of a resin film in which a light shielding agent such as a black pigment, a black dye, and a metal oxide is used as a dispersion.

  The color filter substrate for a liquid crystal display device according to the present invention can be manufactured at low cost, has a low load on the environment, and is more electrically conductive than a metal-based thin film in consideration of electrical shielding with the electrode substrate D. A resin light shielding layer having low conductivity is suitable. In order to maintain the light shielding performance of the liquid crystal display device, the resin light shielding layer preferably has an optical density of 2.1 or more in a thickness range of 0.5 to 1.5 μm.

  Examples of the resin used for the resin light-shielding layer include materials such as epoxy resins, acrylic resins, urethane resins, polyester resins, polyimide resins, polyolefin resins, and photosensitive resins such as gelatin and non-photosensitive resins. Is preferably used.

  As a light-shielding agent used for the resin light-shielding layer, for example, metal oxide powders such as carbon black, titanium oxide, titanium oxynitride, and iron tetroxide, metal sulfide powders, pigments, and mixtures thereof are preferable. Among these, carbon black is inexpensive and can be said to be a suitable material from the viewpoint of manufacturing cost. However, since carbon black has a lower resistance value than metal oxide, it may exhibit conductivity. In this case, stabilization of quality can be obtained by applying the present invention.

  Furthermore, in order to adjust the color tone of the resin light-shielding layer, a complementary color pigment can be mixed. In particular, when only the light-shielding agent is used, the resin light-shielding layer is colored. Therefore, it is preferable that the display characteristics are achromatic. Furthermore, in order to form an inexpensive light-shielding layer, a laminated film using at least two colored regions may be substituted.

  The arrangement of the predetermined pattern formed with the light shielding layer 5 in the display region R of the color filter substrate is typically a stripe arrangement or a delta arrangement, but is not particularly limited.

  The colored region 6 (6R, 6G, 6B) formed on the color filter substrate for a liquid crystal display device of the present invention is not particularly limited as long as it is a configuration necessary for color display, and red, blue, and Three colors of cyan, magenta, and yellow can be used as long as they are green and subtractive colors. In the colored region, a resin in which a colorant such as a pigment or dye is generally used as a dispersion is used, and a pigment such as red, orange, yellow, green, blue or purple is used to obtain desired display characteristics in a liquid crystal display device. And dye colorants are preferably used.

  As the colorant, organic pigments, inorganic pigments, dyes and the like are suitable. The pigment may be subjected to a surface treatment such as rosin treatment, acidic group treatment, basic treatment, or pigment derivative treatment, if necessary. In general, as a symbol for specifying the color of pigments and dyes, color indexes such as PR (Pigment Red), PG (Pigment Green) or PB (Pigment Blue) (CI; issued by The Society of Dyers and Colorours) Used. For formal notation, C.I. I. Is displayed with a specific color symbol (for example, CI PR254 etc.), but in the description of the present invention, the C.I. I. Is omitted (for example, PR254 for CI PR254).

  As the resin component used in the colorant dispersion, for example, photosensitive resins such as acrylic resins, polyimide resins, and epoxy resins, non-photosensitive resins, and mixed materials thereof are preferably used. Further, various additives such as an ultraviolet absorber and a dispersant may be added to the colored region. Examples of the dispersant include a surfactant, a pigment intermediate, a dye intermediate, and a polymer dispersant. A wide range is used. In addition to the color display described here, the color filter substrate for a liquid crystal display device according to the present invention may be formed by using a transparent resin having a transmittance of 85% or more as a colored region for black and white display.

  In the transparent electrode layer 8 for a liquid crystal display device of the present invention, indium / tin oxide (ITO), zinc oxide, tin oxide, or an alloy thereof is preferably used. ITO is particularly preferably used from the viewpoint of electrode characteristics. As a method for forming the transparent electrode layer, a mask material with a predetermined portion of the display area being opened and a substrate are overlapped, and a desired method using a dipping method, chemical vapor deposition, vacuum deposition method, sputtering method, ion plating method, or the like is used. Form in the area. Among them, the sputtering method is preferable in order to obtain a highly uniform electrode, and DC magnetron sputtering that can obtain a high film formation rate is more preferable. However, the present invention is not limited to these.

  Moreover, after forming the transparent electrode layer 8 on the entire surface without using a mask material, a photosensitive photoresist is applied, and the transparent electrode layer is formed only in a predetermined region by etching or laser processing using a photolithography method. It is also possible to do. However, in the electrode substrate D using polycrystalline silicon, a liquid crystal driving circuit is formed in a non-display area around the display area, and therefore an electrical short circuit is formed in the area opposite to the driving circuit on the color filter substrate C. It is necessary to devise not to form the transparent electrode layer that causes the cause, and this causes a decrease in yield in the process of removing the transparent electrode layer in a fine region where the driving circuit is disposed. For example, when forming a transparent electrode layer using a mask material, the mask material and the substrate are held with a certain gap in order to suppress the generation of scratches due to the contact between the mask material and the substrate. Therefore, the transparent electrode layer oozes out in the drive circuit area and causes an electrical short circuit with the drive circuit, or the transparent electrode layer is removed due to defective removal of the drive circuit area even during the etching process. For example, the remaining electrical short circuit may occur, or the display area may lack ITO and display defects may occur. In the case of the present invention, since the insulating layer is formed on the non-display region and the insulation of the driving circuit on the opposing electrode substrate is maintained, the function of the driving circuit is impaired even if the transparent electrode is formed on the entire surface of the substrate. Therefore, a stable yield can be obtained by a simple method, and a sufficient effect can be obtained even in consideration of cost.

  When the transparent electrode layer 8 is formed on the uppermost layer of the color filter substrate for a liquid crystal display device, a transparent protective layer 7 made of at least a resin may be provided between the transparent electrode layer 8 and the colored region 6. The transparent protective layer has the effect of relaxing and flattening the surface step caused by the thickness difference between the light shielding layer 5 of the color filter substrate, the colored region 6 and the colored layers 6R, 6G, 6B. As the resin used for the transparent protective layer 7, for example, any of a thermosetting resin represented by an epoxy resin, an acrylic resin, and a polyimide resin, a photosensitive resin using an acrylic resin, or the like is appropriately used. And can be processed only on the entire surface of the substrate or in a desired region.

  In addition, in the color filter substrate for an IPS liquid crystal display device that is currently used to improve visibility at a wide viewing angle, display is performed by driving the liquid crystal in a plane between drive electrodes provided between the electrode substrates. A transparent electrode layer is not required on the color filter substrate, and the transparent protective layer 7 of the color filter substrate C is the uppermost layer as shown in FIG. When the liquid crystal drive electrode in the display area and the drive circuit for the non-display area are formed and arranged on the IPS liquid crystal display device using polycrystalline silicon, the transparent layer laminated on the uppermost layer of the color filter substrate. An insulating layer may be formed in consideration of electrical characteristics with respect to the protective film layer 7.

  The formation position of the columnar spacers 9 provided on the color filter substrate for a liquid crystal display device of the present invention is not particularly limited, and may be arranged at a desired position as long as the gap between the electrode substrates can be sufficiently retained. it can. However, in order to prevent the display light from being attenuated by the columnar spacer 9, it is preferable to dispose it on the light-shielding region 5 that forms a predetermined pattern around the colored region, not the transmissive portion that forms the colored region 6.

  Although various resin materials can be used as the resin used for the columnar spacer 9, it is preferable to use either a positive type or a negative type photosensitive resin in consideration of its workability and mechanical strength. . For example, as the positive photosensitive resin, a mixture of a novolak resin and a naphthoquinonediadisulfonic acid ester is preferably used. Examples of the negative photosensitive resin include resins such as cyclized rubber-bisazide, phenol resin-azide, acrylic resin, and chemical sensitization. For example, in the case of an acrylic resin, an oligomer having a molecular weight of 1,000 to 2,000 is preferably used. Polyester acrylate, epoxy acrylate such as phenol novolac epoxy acrylate, o-cresol novolac epoxy acrylate, polyurethane acrylate, poly Examples thereof include ether acrylate, oligomer acrylate, alkyd acrylate, melamine acrylate and the like. Polyfunctional photopolymerizable acrylate monomers include 1,4-butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate and dipentaerythritol hexaacrylate. Etc.

  Furthermore, in order to improve the mechanical strength of the columnar spacer 9, various additives may be added to the resin for adjustment. Examples of additives include inorganic particles, extender pigments such as silica, barium sulfate, barium carbonate, calcium carbonate, and talc, colored pigments, and ceramic powder and glass such as alumina, zirconia, magnesia, beryllia, mullite, and cordierite. -Ceramic composite powder or the like is used. Among these, barite, barium sulfate, calcium carbonate, silica, and talc are preferred among extender pigments in terms of strength.

  The method for forming the columnar spacer 9 is not particularly limited, but a photolithography method using a photosensitive resin is preferable from the viewpoint of fine processing. For example, spin coating, curtain flow coating, die coating, etc. are used, a columnar spacer material is applied to the entire surface of the color filter substrate C, the solvent is removed by vacuum drying and / or a hot air dryer, and exposure is performed using a predetermined wavelength region. Examples thereof include a method of removing parts other than a predetermined part after organic alkali or metal alkali development.

  The insulating layer 10 disposed in the non-display area on the color filter substrate C of the present invention is provided at a position including the liquid crystal driving circuit 3 provided on the electrode substrate D, and the color filter substrate of the color filter substrate is interposed via the insulating layer 10. A short circuit between the uppermost layer and the driving circuit 3 is prevented. In particular, in a color filter substrate for a liquid crystal display device using polycrystalline silicon, an insulating layer is formed on the light shielding layer in the non-display area in order to form the liquid crystal drive circuit in the non-display area disposed around the display area. Is preferred.

  The shape of the insulating layer 10 is not particularly limited, but when the columnar spacer provided in the display area extends to the relative position of the liquid crystal driving circuit to form an insulating layer, the exposed area between the transparent electrode layer and the liquid crystal driving circuit is There is a danger that the crushing of the spacer due to external pressure leads to an electrical short circuit. Therefore, it is preferable to form the insulating layer 10 in a rectangular parallelepiped shape provided in the display region R, for example, as shown in the cross-sectional view of FIG. 1 and the front view of FIG. It is particularly preferable that the insulating layer is formed in a trapezoidal shape having a trapezoidal cross-sectional area and the insulating layer has a lower bottom than the upper bottom. In this case, the electrical shielding effect on the lower surface of the insulating layer can be enhanced, the external pressure applied to the upper surface can be evenly distributed, and the gap between the electrode substrate and the color filter substrate can be stably maintained.

  In the present invention, as shown in the front view of FIG. 2, the arrangement method of the insulating layer 10 may be arranged so as to face only the drive circuit region, and the circuit region is included as shown in the front view of FIG. It can also be arranged around the non-display area. However, the arrangement area of the insulating layer for shielding the liquid crystal driving circuit is arranged so as to shield 80% or more of the liquid crystal driving circuit area, and the insulating layer 10 is uniformly exposed to the liquid crystal driving circuit 3. It is preferable to arrange them, and there is no bias of electric charge depending on the exposed area of the driving circuit, and the effect of suppressing electrical short-circuiting can be enhanced. If it is arranged so as to shield preferably 90% or more, the occurrence of an electrical short circuit is further reduced, but there is no risk that the process yield will be lowered in consideration of the processing accuracy of the insulating layer 3, and for liquid crystal driving. In order to suppress leakage generated from the exposed portion of the circuit 3, a highly reliable liquid crystal display device can be obtained if it is arranged so as to shield 100% or more.

  When the height from the lowermost part of the light shielding layer 5 ′ in the non-display area to the uppermost layer of the insulating layer 10 is hi, and the height of the uppermost part of the columnar spacer 9 from the uppermost part of the light shielding layer 5 in the display area is hs, When | hi−hs | ≦ 1.0 μm is satisfied, the substrate gap in the central portion and the peripheral portion in the display region becomes uniform. More preferably, if | hi−hs | ≦ 0.5 μm, the uniformity of the entire display region. And quality is stabilized.

  Usually, the insulating layer forming portion on the light shielding layer 5 that forms the columnar spacer 9 in the display area and the light shielding layer 5 ′ in the non-display area have a different laminated structure, so the columnar spacer 9 and the insulating layer are formed on the color filter substrate. When 10 is processed at the same time, the height on the color filter surface may be different. The light shielding layer 5 'portion in the non-display area does not directly contribute to display. However, if the substrate gap is significantly different from that in the display area, the optical characteristics change in the display area adjacent to the non-display area and display quality deteriorates. Referring to FIGS. 1 and 2, the columnar spacers are arranged between the colored regions arranged in the vertical direction in the drawing on the pattern of the light shielding layer 5 arranged in the display region. In this case, when the striped coloring material is formed so as to cross between the colored regions arranged in the vertical direction in the figure, the colored columnar spacer forming portion has a laminated structure of the light shielding layer and the coloring material. Since the insulating layer 10 formed in the display region UR is formed on the light shielding layer, the height from the lowermost portion of the light shielding layer is lower than that of the columnar spacer.

  Therefore, the design of the shape of the colored region and the shape of the light-shielding part is changed to form a region where no colored region exists on the light-shielding part, and a columnar spacer is formed on that part to provide on the light-shielding layer of the non-display region It is possible to make the height of the insulating layer the same, or to form a colored region that does not participate in display on the light shielding layer as shown in FIG. Is possible. Either method is effective as a means for making the substrate gap between the display area and the non-display area uniform.

  Compared to the case where the insulating layer shown in FIG. 2 is formed only in the driving circuit region, the substrate gap between the display region and the non-display region is more uniform when the insulating layer shown in FIG. 4 is formed around the non-display region. Although good, the display quality can also be improved by adjusting the substrate gap holding means outside the drive circuit area even in the embodiment of FIG.

  A method for forming the insulating layer 10 provided on the color filter substrate for the liquid crystal display device of the present invention is not particularly limited, but a resin containing an insulating material is applied to the entire surface of the predetermined color filter substrate provided with the columnar spacers 9. In addition, a method of forming an insulating layer in a predetermined portion by a photolithography method, a method of forming an insulating layer by vapor-depositing an insulating material while shielding other than a predetermined region, and the like can be given.

  However, since the increase in the number of steps causes an increase in manufacturing cost and a decrease in yield, the method of forming the insulating layer 10 simultaneously in the step of forming the columnar spacers 9 is more preferable. That is, when the columnar spacers 9 are formed by photolithography, the method of forming them simultaneously by exposure and development is optimal by including the insulating layer pattern in advance in a desired region on the photomask. . Further, when an additive capable of obtaining an insulating effect is contained in the material of the columnar spacer 9, any of the columnar spacer materials shown above can be used, and the degree of freedom in material selection is widened and suitable. In particular, inorganic materials such as silica, titanium oxide, titanium nitride, and titanium oxynitride can be used. However, the material is not particularly limited, and any material that exhibits a desired effect can be used.

In order for the insulating layer 10 to exert an electrical shielding effect on the liquid crystal driving circuit 3, it is preferable that the volume resistance value of the insulating layer 10 is greater than or equal to the volume resistance value of the uppermost layer of the color filter substrate. . That is, since the volume resistance value of the insulating layer acts on a leakage current conducted from the liquid crystal driving electrode 10 provided on the electrode substrate D to the color filter substrate, the volume resistance value of the insulating layer 10 is Ri and the color filter substrate. Assuming that the volume resistance value of the uppermost layer is Rt, in order to prevent a short circuit with the uppermost layer of the color filter substrate, an effect is exhibited by providing an insulating layer satisfying the relationship of Ri ≧ Rt. In particular, when the transparent electrode layer 8 is formed in the uppermost layer shown in FIG. 1, if an electrical short circuit occurs between the liquid crystal driving circuit 10 and the transparent electrode layer 8 as a conductor, a malfunction occurs, Even in the case of the closest contact, circuit breakdown occurs due to a discharge phenomenon in the vicinity of the drive circuit on the electrode substrate D. Therefore, the difference between the volume resistance values Ri and Rt is preferably Ri−Rt ≧ 10 ⁴ (Ω / cm). .

  By making the relative dielectric constant of the insulating layer 10 greater than or equal to the relative dielectric constant of the uppermost layer of the color filter substrate, the reliability of the liquid crystal display device using the color filter substrate is increased. In particular, if the dielectric constant of the insulating layer is higher than the dielectric constant of the top layer of the color filter substrate, the dielectric polarization in the insulating layer increases the frequency of electrostatic breakdown on the electrode substrate around the drive circuit, resulting in overcurrent. Cause malfunction or destruction of the circuit. Therefore, when the dielectric constant of the insulating layer 10 is Ei and the dielectric constant of the uppermost layer on the color filter substrate is Et, the relationship between the two should satisfy the relationship of Ei−Et ≧ 0.

  Thus, in the present invention, a liquid crystal display in which a liquid crystal driving electrode and a liquid crystal driving circuit for transmitting a signal to the liquid crystal driving electrode are formed on the electrode substrate using a material having a high electric field transfer effect effect such as polycrystalline silicon. Suitable for the device.

  As a specific example of fabricating a TFT for a liquid crystal driving electrode on an electrode substrate using polycrystalline silicon, a bottom gate type manufacturing method is shown below. However, a TFT and a driving circuit exist on the electrode substrate. For example, the production method is not particularly limited.

A chromium thin film is formed on the substrate 1 by sputtering, and a gate electrode is formed by photolithography. Next, a silicon nitride film and an amorphous silicon film are stacked as an insulating layer of the gate electrode by plasma CVD, and then heated in vacuum to perform dehydrogenation. Further, a photoresist pattern is formed on the amorphous silicon layer with portions serving as the source and drain electrodes of the TFT as opening regions, and phosphorus (P) ions are implanted (doping) into the opening regions. An amorphous silicon thin film is irradiated with an excimer laser to crystallize and activate impurities, and after patterning silicon, source and drain electrodes are formed by a Ti thin film, and a SiO ₂ thin film is deposited on the upper layer. Finally, the opening of the electrode part and hydrogen plasma treatment are performed to form a TFT. The light transmission area arranged in a predetermined pattern in the display area on the electrode substrate is provided with a pixel electrode made of a transparent electrode layer, and voltage application is performed in response to an on / off signal from the connected TFT. To drive the liquid crystal. Here, the portion composed of the TFT and the pixel electrode is collectively referred to as a liquid crystal driving electrode 2. A signal input to the TFT can be obtained from the driving circuit 3 formed using polycrystalline silicon on the same substrate. Although protective films and insulating films are formed on the electrodes and circuits, the present inventors have found that these thin films are insufficient in electrical short-circuiting.

A chromium thin film is formed on the substrate 1 by sputtering, and a gate electrode is formed by photolithography. Next, a silicon nitride film and an amorphous silicon film are stacked as an insulating layer of the gate electrode by plasma CVD, and then heated in vacuum to perform dehydrogenation. Further, a photoresist pattern is formed on the amorphous silicon layer with portions serving as the source and drain electrodes of the TFT as opening regions, and phosphorus (P) ions are implanted (doping) into the opening regions. An amorphous silicon thin film is irradiated with an excimer laser to crystallize and activate impurities, and after patterning silicon, source and drain electrodes are formed by a Ti thin film, and a SiO ₂ thin film is deposited on the upper layer. Finally, the opening of the electrode part and hydrogen plasma treatment are performed to form a TFT. The light transmission area arranged in a predetermined pattern in the display area on the electrode substrate is provided with a pixel electrode made of a transparent electrode layer, and voltage application is performed in response to an on / off signal from the connected TFT. To drive the liquid crystal. Here, the portion composed of the TFT and the pixel electrode is collectively referred to as a liquid crystal driving electrode 2. A signal input to the TFT can be obtained from the driving circuit 3 formed using polycrystalline silicon on the same substrate. Although protective films and insulating films are formed on the electrodes and circuits, the present inventors have found that these thin films are insufficient in electrical short-circuiting.
(Preparation of counter substrate with electrode) Next, a counter substrate provided with a thin film transistor element was manufactured by the following procedure. First, after patterning a gate electrode and a common electrode by a photo-etching technique using chromium on an alkali-free glass, an insulating film made of a silicon nitride (SiN) film was formed so as to cover these electrodes. An amorphous silicon (a-Si) film was formed on the gate insulating film, and a source electrode and a drain electrode were formed on the film using aluminum. At that time, the electrode was patterned so that an electric field was applied between the common electrode and the drain electrode in a direction parallel to the substrate. A protective film was formed with an SiN film on these electrodes. Finally, a polyimide-based alignment film was provided on the uppermost layer, and a rubbing process was performed to obtain a counter substrate with electrodes having a thin film transistor.

  Finally, a liquid crystal display device will be described. The following parts are general outlines of the device and are not particularly limited, and are omitted in the drawings.

  A color filter for a liquid crystal display device is manufactured by bonding a liquid crystal driving electrode, a liquid crystal driving circuit, an electrode substrate provided with a gate line and a signal line for connecting them, and a color filter substrate to face each other. An alignment film is provided on at least one of the substrates, and an alignment process such as rubbing is performed. After the alignment treatment, the electrode substrate and the color filter substrate are bonded together using a sealant, and after injecting liquid crystal from an injection port provided with a part of the seal portion cut away, the injection port is sealed. Subsequently, a polarizing plate is bonded to an untreated surface on at least one of the substrates. Finally, a circuit in which a logic circuit other than the liquid crystal driving circuit formed on the electrode substrate is mounted on the TAB film is connected from the outside of the apparatus to complete. In the drawing of the present invention, each part used for the above color filter for a liquid crystal display device is omitted.

  The color filter for a liquid crystal display device of the present invention and the liquid crystal display device using the same are suitably used for light valves and small viewfinders for notebook PCs, monitors, TVs and projectors, and in particular, cellular phones and portable information terminals. In order to obtain the maximum display image while storing the display medium in a limited area, etc., a liquid crystal driving circuit is formed on the electrode substrate and polycrystalline silicon arranged in the liquid crystal display device is used as the electrode material. It is suitably used for a liquid crystal display device.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Reference example 1
[Production of liquid crystal display devices]
Two transparent non-alkali glass substrates (Corning # 1737) were used, and one substrate used was an electrode substrate having a predetermined display area, and the other substrate was used as a color filter substrate and bonded together. .

(Production of electrode substrate)
The electrode substrate having the following configuration was used.

  A rectangular display area was set on a transparent substrate, and the liquid crystal drive electrodes 2 were arranged in a matrix. The TFT included in the liquid crystal drive electrode 2 is made of polycrystalline silicon, and the pixel electrode is formed using a transparent electrode layer through which display light is transmitted. Further, the liquid crystal driving circuit 3 is provided on one side of the non-display area around the display area at a position 400 μm away from the display area. The liquid crystal driving circuit was arranged in a rectangular area with dimensions of 1200 μm × 2500 μm.

(Production of color filter substrate)
The color filter substrate was produced as follows.

  A position facing the display area arranged on one of the electrode substrates is set as a display area, a colored area 6 is formed at a position corresponding to the electrode pattern for driving the liquid crystal, and the resin light-shielding layer 5 is formed between the colored areas and between the non-display areas. Formed. After the red, blue and green colored layers were alternately arranged in the colored region, ITO films were laminated in this order as the transparent protective layer 7 and the transparent electrode layer 8 on almost the entire surface of the color filter substrate. Subsequently, using a resin made of a photosensitive acrylic material on the ITO film, a columnar spacer 9 is provided on the light-shielding layer between the colored regions at predetermined positions, and then at a position facing the liquid crystal driving circuit 3 on the electrode substrate. An insulating layer 10 was formed to obtain a color filter substrate.

  The production method will be described in detail below.

(1) Preparation of light-shielding layer A 20 L reaction kettle equipped with a thermometer, dry nitrogen inlet, heating / cooling device with hot water / cooling water, and a stirrer was charged with γ-butyrolactone 16644.1 g, 4, 4′- 600.7 g of diaminodiphenyl ether, 670.2 g of 3,3′-diaminodiphenylsulfone, and 74.6 g of bis-3- (aminopropyl) tetramethylsiloxane were added, and the kettle was heated to 30 ° C. After 30 minutes, 644.4 g of 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 641.3 g of pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 294.2 g of anhydride was charged and the kettle was heated to 58 ° C. Three hours later, 11.8 g of maleic anhydride was added, and the mixture was further heated at 58 ° C. for 1 hour to obtain an NMP solution (B1) of polyamic acid.

  Carbon black 4.6 g, polyamic acid solution (B1) 24.0 g, N-methylpyrrolidone 61.4 g were dispersed together with glass beads 90 g using a homogenizer at 7000 rpm for 30 minutes, and then the glass beads were removed by filtration. A mill base was obtained.

  Also, Pigment Blue 15: 6 2.2 g, polyamic acid solution (A1) 24.0 g, N-methylpyrrolidone 63.8 g were dispersed together with 90 g of glass beads with a homogenizer at 7000 rpm for 30 minutes, and then the glass beads were filtered. This was removed to obtain a blue pigment mill base. By mixing all the obtained mill bases, a paste for a resin light-shielding layer was obtained.

  A resin black matrix paste is spin-coated on a glass substrate, and is heated and dried in air in an oven at 50 ° C. for 10 minutes, 90 ° C. for 10 minutes, and 110 ° C. for 20 minutes to obtain a polyimide film having a thickness of 1.1 μm. A precursor colored film was obtained. A positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on this film, and dried by heating at 80 ° C. for 20 minutes to obtain a resist film having a thickness of 1 μm. Using a UV exposure machine PLA-501F manufactured by Canon Inc., an ultraviolet ray having an intensity at a wavelength of 365 nm of 50 mJ / cm 2 was irradiated through a photomask made of chromium. After the exposure, the photoresist and the polyimide precursor colored coating were developed at the same time by immersing in a developer composed of a 2.38 wt% aqueous solution of tetramethylammonium hydroxide. After etching, the unnecessary photoresist layer was peeled off with methyl cellosolve acetate. Furthermore, the polyimide precursor colored film thus obtained was heat-treated at 300 ° C. for 30 minutes in a nitrogen atmosphere, and a polyimide colored pattern film having a film thickness of 1.0 μm comprising a lattice-like pixel portion and a frame portion surrounding them was formed. Obtained.

(2) Formation of colored region Pigment Red 177, Pigment Green 36, and Pigment Blue 15: 6 are prepared as red, green and blue pigments, respectively, mixed and dispersed with the polyamic acid solution (P1), and red, blue Three types of green colored pastes were obtained. The obtained red paste was spin-coated on a resin black matrix substrate, dried by heating in air using an oven at 50 ° C. for 10 minutes, 90 ° C. for 10 minutes, and 110 ° C. for 20 minutes to obtain a film thickness of 1.2 μm. The polyimide precursor colored film was obtained. A positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on this film and dried by heating at 80 ° C. for 20 minutes to obtain a resist film having a thickness of 1.1 μm. Using a UV exposure machine PLA-501F manufactured by Canon Inc., an ultraviolet ray having an intensity at a wavelength of 365 nm of 50 mJ / cm 2 was irradiated through a chrome photomask in addition to the colored region forming part. After the exposure, the photoresist and the polyimide precursor colored coating were developed at the same time by immersing in a developer composed of a 2.38 wt% aqueous solution of tetramethylammonium hydroxide. After development, the unnecessary photoresist layer was peeled off with methyl cellosolve acetate. Furthermore, the polyimide precursor-colored film thus obtained was heat-treated at 300 ° C. for 30 minutes in a nitrogen atmosphere to obtain a polyimide red pattern film having a thickness of 1.0 μm. Similarly, green paste and blue paste patterns were formed to obtain a color filter base plate having three primary colors of red, green and blue.

(3) Formation of transparent protective film A thermosetting acrylic resin solution (Optomer 6917 manufactured by JSR) was used for the obtained color filter substrate, and the entire surface of the substrate on which the color filter substrate was formed was spin-coated, and then at 100 ° C. for 5 minutes. And heated at 260 ° C. for 30 minutes. The rotational speed of spin coating was adjusted so that the film thickness after heating was 1.5 μm, and a transparent protective film was formed. The transmittance of the protective film layer was 98% or more at a wavelength of 550 nm, and it was confirmed that a desired protective film could be obtained.

(4) Formation of transparent electrode layer An ITO film was formed at 130 ° C. in a vacuum by a DC magnetron sputtering method. Next, annealing was performed at 220 ° C. to provide a transparent electrode layer to obtain a color filter original plate. The thickness of the ITO film was 140 nm. The refractive index of ITO has a refractive index of 1.80 to 2.50 at a wavelength of 400 nm, a refractive index of 1.60 to 2.20 at a wavelength of 550 nm, and a refractive index of 1 at a wavelength of 700 nm. It was confirmed with a spectroscopic ellipsometer that it was .50 or more and 2.10 or less, and it was confirmed that the ITO film had desired electrical characteristics.

(5) Formation of columnar spacers After applying a negative photosensitive acrylic resin (Optoma NN800, JSR) by spin coating, the solvent was removed by heating to 80 ° C. in a vacuum of 60 Pa. Next, using a UV exposure machine PLA-501F manufactured by Canon Inc., the pattern forming portion of the columnar spacer forming portion was irradiated with ultraviolet rays having a wavelength of 365 nm of 100 mJ / cm ² through a chromium photomask. Thereafter, after exposure, the film was immersed in a developer composed of a 0.02 wt% aqueous solution of tetramethylammonium hydroxide and developed so as to remove the unexposed areas. Finally, the resin pattern obtained after development was heated in a nitrogen atmosphere at 250 ° C. for 30 minutes to complete the reaction. The height of the columnar spacer was prepared such that the height after being coated on the entire surface of the glass substrate and cured in the same process as described above was 3.0 μm.

(6) Formation of insulating layer A photosensitive acrylic resin solution (JSR Optoma NN700) was used to form the insulating layer by the following method. After applying the resin solution by spin coating, the solvent was removed by heating to 80 ° C. in a vacuum of 60 Pa. Next, using a UV exposure machine PLA-501F manufactured by Canon Inc., a resin pattern is formed by irradiating a region corresponding to a liquid crystal driving circuit with ultraviolet light having a wavelength of 365 nm of 100 mJ / cm ² through a chromium photomask. did. Then, it was immersed in the developing solution which consists of 0.02 wt% aqueous solution of tetramethylammonium hydroxide, and developed so that an unexposed part might be removed. Finally, the reaction of the insulating layer formed at a desired position was completed by heating the resin pattern obtained after development in a nitrogen atmosphere at 250 ° C. for 30 minutes. Similarly to the height of the columnar spacer, the insulating layer was prepared so that the height obtained after curing on the glass substrate in a predetermined process was 3.2 μm.

  The height of the columnar spacer and the insulating layer from the lowermost part of the light shielding area in the display area provided on the color filter substrate was measured as follows. First, sandwich a columnar spacer or insulating layer to be measured to expose at least two neighboring glass substrate surfaces, and then use a stylus type surface step meter DEKTAK FPD-500 manufactured by Nippon Vacuum Co., Ltd. The portion between the exposed portions was scanned across the top of the measurement target, and the level difference between the exposed portion and the top of the measurement target portion was determined. At this time, the measurement is performed at least five times while changing the scanning part so as to pass through the top of one columnar spacer or one part of the insulating layer to be measured, and the 10-point measurement average value in the color filter substrate is a representative value. Used as. As a result of the measurement, the height from the lowermost part of the light shielding area in the display area to the upper part of the columnar spacer and the height from the upper part of the insulating layer were both 5.7 μm.

  The relative dielectric constant of the resin material forming the columnar spacer and the insulating layer was measured by an impedance analyzer A4294 manufactured by Agilent Technologies using a general three-terminal method. To explain the outline, a resin material is applied on the entire surface of an aluminum substrate with a film thickness of 5 μm, and a circular electrode having the same diameter as the terminal diameter and a gap of about 5 mm are provided on the coating film by aluminum deposition to surround the circular electrode. A notched concentric guard electrode was prepared and used as a measurement sample. As a result, the dielectric constant of the resin material can be obtained by regarding the gap between the circular electrode portion and the aluminum substrate as a capacitor.

On the other hand, the volume resistance value was calculated by measuring the current against the applied voltage between the circular electrode and the aluminum substrate using a pA meter manufactured by Hured Packard Co. using the above-mentioned sample. As a result, the resin material used in this example had a relative dielectric constant of 3.9 and a volume resistance of 1.6 × 10 ¹⁶ Ω · cm when an alternating voltage with a frequency of 1 kHz was applied. Moreover, as a result of measuring a 0.2 μm ITO film by the same method, the relative dielectric constant was 20000 or more, and the volume resistance was 5.8 × 10 ⁻⁴ Ω · cm.
Met.

(Production of liquid crystal display device)
In manufacturing the liquid crystal display device, the configuration of the liquid crystal panel portion will be described first. After applying and heating a polyimide alignment film on the electrode substrate and the color filter substrate and applying a rubbing treatment, a sealant was printed on the periphery and bonded and heat-adhered. In the case of the present invention, the gap between the substrates was held by a columnar spacer and was 2.8 μm after the liquid crystal was sealed. Next, liquid crystal was injected and filled from an inlet provided by previously cutting out the seal portion, and the inlet was sealed using a photosensitive resin. Finally, using two polarizing plates [G1220DU manufactured by Nitto Denko Corporation], the panel was sandwiched from the outside of the electrode substrate and the color filter substrate to obtain a liquid crystal panel portion.

  Further, a circuit other than the liquid crystal driving circuit such as a logic circuit for sending a signal to the liquid crystal driving circuit and a power supply component was previously formed on the TAB film # 7100 manufactured by Toray. A liquid crystal display device was obtained by connecting and mounting the connection part of the liquid crystal panel part and the terminal part of the TAB film.

(Evaluation of color filters for liquid crystal display devices)
Based on this example, 100 color filters for a liquid crystal display device were produced, and the display state was observed. X indicates that there is a display defect due to obvious drive failure due to short circuit between the drive circuit and the transparent electrode layer, △ indicates that the display defect does not occur completely, and △ indicates that the display defect occurs sporadically. Was classified as ○. As a result, as shown in Table 1, X was 1, Δ was 5, and ○ was 94. As a result of observing the insulating layer portion of the liquid crystal display device in which the display failure occurred, x and Δ were missing resin patterns in the insulating layer, and an electrical short circuit at the missing portion could be identified as the cause of the failure. Further, the state of the display defect changes depending on the missing area, and the case where the missing is small is Δ. Further, 10 out of 93 of the ○ sections were observed by random extraction, but no missing portion of the insulating layer occurred. Therefore, it was confirmed that the effects of the present invention can be obtained when the insulating layer is normally formed.

Reference example 2
(Production of color filter substrate)
A liquid crystal display device was produced in the same manner as in Reference Example 1 except that a columnar spacer and an insulating layer were simultaneously formed on the ITO film using the color filter substrate on which the ITO film described in Reference Example 1 was laminated.

(Evaluation of color filters for liquid crystal display devices)
A negative photosensitive acrylic resin (Optoma NN800, JSR) was spin-coated on a color filter substrate laminated up to an ITO film, and then the solvent was removed by heating to 80 ° C. in a vacuum of 60 Pa. Next, using a UV exposure machine PLA-501F manufactured by Canon Inc., the intensity at a wavelength of 365 nm is 100 mJ / cm ² through a chromium photomask in which the pattern formation region of the columnar spacer and the insulating layer is an opening. The ultraviolet rays were irradiated. Then, after exposure, the film was immersed in a developer composed of a 0.02 wt% aqueous solution of tetramethylammonium hydroxide, developed to remove the unexposed areas, and finally the resin pattern obtained after development was subjected to a nitrogen atmosphere. The reaction was completed by heating at 250 ° C. for 30 minutes. In this color filter substrate, the height of the columnar spacer and the insulating layer was adjusted so that the height of the cured film after coating on the entire glass substrate was 3.0 μm. The height to the upper part was 5.7 μm, and the height to the upper part of the insulating layer was 5.5 μm in the same measurement. The dielectric layer had a relative dielectric constant of 3.8 and a volume resistance of 2.1 × 10 ¹⁶ Ω · cm when an alternating voltage with a frequency of 1 kHz was applied.

Further, as a result of manufacturing a liquid crystal display device using this color filter substrate, the gap between the two substrates held by the column spacer is 2.9 μm after the liquid crystal is sealed, and the display state of 100 liquid crystal display devices As a result of the observation, the occurrence of defects due to short-circuiting between the electrode substrate and the color filter substrate, that is, the defect that the effect of the insulating layer is estimated to be insufficient is as follows: x is 2; Δ is 4; It was a piece. As a result of observing the defective devices of × and Δ, there were six devices in which a part of the insulating layer was missing and the ITO layer was exposed as in Reference Example 1 . In the remaining four, the insulating layer is formed so as to be shifted from the region facing the driving circuit, and the ITO layer is exposed at a position partially facing the driving circuit. Therefore, the effect of the present invention was recognized when the insulating layer was normally formed.

Example 3
(Production of electrode substrate)
A so-called IPS mode liquid crystal in which a comb-shaped electrode is employed as a liquid crystal driving electrode by a horizontal electric field on an electrode substrate, two comb-shaped electrodes are alternately combined in a pixel region, and a polycrystalline silicon TFT is used as a switching element. A display device was used.

(Production of color filter substrate)
Except that the uppermost layer of the color filter substrate on which the columnar spacer and the insulating layer are formed becomes the transparent protective film 7, the light shielding layer and the colored region have the same configuration as in Reference Example 1 . For the columnar spacer and the insulating layer, a photosensitive acrylic resin (Optomer NN700, JSR Co., Ltd.) whose relative dielectric constant and volume resistance are known from Reference Example 1 is used, whereas the transparent protective film has a relative dielectric constant and volume resistance of 4 each. 5 and 2.4 × 10 ¹⁵ Ω · cm.

The columnar spacer and the insulating layer on the transparent protective film were collectively formed by the same method as in Reference Example 2 and adjusted so that the height of the cured film on the glass substrate was 3.0 μm. As a result, the height from the lowermost part of the light shielding area in the display area to the upper part of the columnar spacer was 5.5 μm, and the same measurement was performed to a height of 5.2 μm to the upper part of the insulating layer. The insulating layer material used was the same as in Reference Example 2 .

As a result of performing the same evaluation as in Reference Example 1 using this color filter substrate, the number estimated to be defective due to an electrical short circuit with the electrode substrate in 100 liquid crystal display devices was 0 for x and Δ, ○ was 100, and the effect of the insulating layer was recognized.

Comparative Example 1
The electrode substrate was the same as in Reference Example 1, and the color filter substrate was the same as in Reference Example 1 in which ITO as a transparent electrode layer was laminated on the top layer, but the columnar spacer and insulating layer were formed. There wasn't.

In the production of the liquid crystal display device, the gap between the electrode substrate and the color filter substrate was held using ceramic beads having an average particle size of 3.0 μm (Micropearl from Sekisui Chemical Co., Ltd.). That is, a polyimide-based alignment film was applied and heated on the electrode substrate and the color filter substrate, and after rubbing, ceramic beads were dispersed so as to be uniformly distributed, and a sealant was heated and adhered to the periphery. The subsequent manufacturing procedure was performed in the same manner as in Reference Example 1. As a result, the gap between the substrates was 2.8 μm after the liquid crystal was sealed.

100 liquid crystal display devices were produced in the same manner as in Reference Example 1, and the display state was observed. There are 16 display defects that are presumed to be caused by a short circuit between the liquid crystal drive circuit and the transparent electrode layer, x is not completely short-circuited, and 48 display defects occur sporadically. There were 36 ◯ not. When 64 x and Δ liquid crystal display devices were observed, there were 51 ceramic beads on the non-display area where the driving circuit was located. As a result, it was determined that the exposed area of the driving circuit was large and shorted with the transparent electrode layer on the color filter substrate. In addition, as a result of observing the remaining 13 liquid crystal display devices, it was found that the ceramic beads destroyed the liquid crystal driving circuit during bonding.

Comparative Example 2
A columnar spacer 9 using a photosensitive acrylic material (Jptor Optmer NN700) having a known relative permittivity and volume resistance is provided on a light shielding layer between colored regions at predetermined positions on a color filter substrate, and further a driving circuit. A columnar spacer formed in the display area was also extended in the non-display area including the area, and a liquid crystal display device was manufactured in the same manner as in Reference Example 1 except that.

  As a result of observing 100 liquid crystal display devices in the same manner as others, it was estimated that 18 was caused by a short circuit between the liquid crystal driving circuit and the transparent electrode layer, and 32 display defects were sporadic. The number of o where no occurred was 50. By observing 50 x and Δ liquid crystal display devices, 8 defects were found due to the lack of column spacers in the drive circuit area, but the remaining 42 had no problem with column spacers. As a result of further investigation of the cause, it was determined that the arrangement effect of the columnar spacers arranged in the display region is poor in the shielding effect of the driving circuit region, and it is difficult to exert the same effect as the insulating layer according to the present invention. .

Comparative Example 3
Insulating with a ceramic acrylic bead between the color filter substrate and the electrode substrate, and using a photosensitive acrylic resin solution (JSR Optoma NN700) with known volume resistance and relative dielectric constant in the drive circuit area on the electrode substrate A liquid crystal display device was produced in the same manner as in Reference Example 1 except that the layer was formed.

As in Reference Example 1 , 100 ceramic beads were prepared in the same manner as in Reference Example 1 , with an average particle size of 2.8 μm and an insulating layer with a cured insulating layer height of 4.0 μm applied on the entire surface of a glass substrate. Although the display state was confirmed, display unevenness was observed mainly in the non-display area where the insulating layer was formed in all the liquid crystal display devices. When a liquid crystal display device having the same configuration was further fabricated and the gap between the electrode substrate and the color filter substrate was measured after the liquid crystal was sealed, the display unevenness portion was 3.7 μm, whereas the normal display portion was 3.1 μm. It was. As a result, the present liquid crystal display device has a high insulating layer height, so it was determined that a display defect occurred with a wider substrate gap around the insulating layer than in the normal part.

Comparative Example 4
As in Example 1 , the uppermost layer is a protective film layer, and ceramic beads having an average particle diameter of 2.8 μm are dispersed on the display area of the color filter substrate on which the transparent electrode layer is not laminated, and the driving circuit on the electrode substrate A liquid crystal display device was manufactured using a color filter substrate in which an insulating layer using a conductive resin was formed in a non-display region of the color filter substrate facing the region.

The conductive resin is a homogenizer dispersing machine together with zirconia beads together with a mixture obtained by adding 5 parts by weight of carbon black (Mitsubishi Chemical Corporation MA-100) as conductive fine particles to 95 parts by weight of a photosensitive acrylic resin solution (JSR Optomer NN700). And dispersed at 7000 rpm for 30 minutes. The insulating layer was formed with a height of 5.5 μm from the lowermost part of the light shielding region where the insulating layer was formed to 5.5 μm. The relative dielectric constant measured by the same method as in Reference Example 1 was 23.1, and the volume resistance value was It was 4.1 × 10 ⁶ Ω · cm.

As a result of evaluating the liquid crystal display device by the same method as in Reference Example 1 , it was found that there were × 28 pieces, 54 pieces of Δ, and 18 pieces of ○. The above was not recognized, and the shielding property with respect to the drive circuit area was sufficiently maintained. Therefore, the inventor pays attention to the relationship between the transparent protective film on the color filter substrate and the insulating layer provided thereon, and the relative dielectric constant and volume resistance of the transparent protective film layer are the same as those in the measurement in Reference Example 1. As a result of measurement by the method, the relative dielectric constant was 4.5, and the volume resistance value was 2.4 × 10 ¹⁶ Ω · cm.

Therefore, high insulating layer dielectric constant of which is located between the protective film on the liquid crystal driving circuit and the color filter substrate on the electrode substrate, their low volume resistivity, the charge from the driving circuit side to the color filter substrate It was judged that an electric field due to bias, i.e., polarization, was induced and the operation of the driving circuit became unstable or electrostatic breakdown proceeded. The results are shown in Table 1.

IPS mode liquid crystal display device using a color filter and for it IPS mode liquid crystal display device of the present invention, notebook PC, the monitor, suitably used in the light valve and small viewfinder for TV and projector, in particular, a mobile phone In order to obtain the maximum display image while storing a display medium such as a portable information terminal or the like in a limited area, a liquid crystal driving circuit is formed on the electrode substrate and the polycrystalline silicon arranged in the liquid crystal display device is used as an electrode. It is suitably used for an IPS liquid crystal display device used as a material.

It is a schematic sectional drawing of the color filter substrate for liquid crystal display devices formed by forming the columnar spacer and insulating layer of this invention on a transparent electrode layer. It is a schematic front view of the color filter substrate for liquid crystal display devices which forms the columnar spacer and insulating layer of this invention on a transparent electrode layer. It is a schematic sectional drawing of the color filter substrate for liquid crystal display devices formed by forming the columnar spacer and insulating layer of this invention on a transparent protective film. 1 is a schematic front view of a color filter substrate for a liquid crystal display device in which an insulating layer according to the present invention is formed over a light shielding layer. It is a schematic sectional drawing of the color filter substrate for liquid crystal display devices formed by forming the insulating layer of this invention through the coloring material provided on the light shielding layer.

Explanation of symbols

R: Display area
UR: non-display area
D: Electrode substrate
C: Color filter substrate 1, 1 ': Substrate
2: Electrode for driving liquid crystal
3: Liquid crystal drive circuit
3 ': Circuit area for driving liquid crystal
4: Insulating film 5, 5 ′: Light shielding layer
6: Colored area
7: Transparent protective film
8: Transparent electrode layer
9: Columnar spacer 10, 10 ': Insulating layer
11: Liquid crystal layer

Claims (5)

A liquid crystal layer is sandwiched between an electrode substrate and a color filter substrate, and the electrode substrate is a non-display in which a display region in which liquid crystal driving electrodes are arranged in at least a predetermined pattern and a liquid crystal driving circuit are provided on the substrate. The color filter substrate includes a columnar spacer disposed on a display region provided with a plurality of colored regions at positions corresponding to the liquid crystal driving electrodes of the electrode substrate and the non-circular region formed around the display region. the ratio of have a insulating layer in a position corresponding to the liquid crystal driving circuit of the display region, the insulating layer and the volume resistivity of the columnar spacers is color filter volume resistivity of the substrate top layer and the same or greater, and the insulating layer and the columnar spacers A color filter substrate for an IPS liquid crystal display device, wherein the dielectric constant is the same as or smaller than that of the uppermost layer of the color filter substrate. 2. The color filter substrate for an IPS liquid crystal display device according to claim 1, wherein the insulating layer is formed using the same material as the columnar spacer. IPS type color filter substrate for a liquid crystal display device according to claim 1 or 2, wherein an insulating layer is formed in a rectangular parallelepiped shape having a cross-sectional area of trapezoidal shape. The relationship between the height hi of the insulating layer formed on the light shielding area of the non-display area from the bottom of the light shielding area and the height hs of the columnar spacer formed on the light shielding area of the display area from the bottom of the light shielding area. | hi-hs | IPS type color filter substrate for a liquid crystal display device according to any one of claims 1 to 3, characterized in that satisfy ≦ 1.0 .mu.m. IPS mode liquid crystal display device using the IPS type color filter substrate for a liquid crystal display device according to any one of claims 1-4.

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