JP2006178301A - Liquid crystal display device and method of fabricating the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with excellent display quality by strictly controlling a gap between substrates (a cell gap) at a low cost. <P>SOLUTION: Two sheets of mutually opposing substrates are adhered to each other by using an inorganic insulator film as a spacer member to control cell thickness, and arranging wall shaped spacers composed of the inorganic insulator film so as to catch both sides of a sealing material 150 (an adhesive) to stick the two sheets of mutually opposing substrates to each other in the gap. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device using a spacer made of a wall-like inorganic material formed by patterning, and a method for manufacturing the same.

  A liquid crystal display device is a device having a structure in which a pair of substrates having electrodes on the surface are opposed to each other and a liquid crystal material is sandwiched between the substrates, and the polarization state of the liquid crystal material is changed according to the voltage applied between the electrodes. Control and output an image. A transmissive, reflective, or transflective liquid crystal display device is used in many devices.

FIG. 7 is a conceptual cross-sectional view of a conventional reflective liquid crystal display device. A Si substrate 110 having a driving circuit and a reflective electrode formed on the surface and a glass substrate 120 having a transparent electrode formed on the surface are arranged to face each other, and the Si substrate 110 and the glass substrate 120 are bonded to each other by a sealing material 150. It is fixed and a cell is formed. A liquid crystal material 130 is sealed in the cell, and a spacer 140 is placed in at least one of the liquid crystal material 130 and the sealing material 150 in order to strictly control the substrate gap (cell gap). Conventionally, as the spacer 140, a spherical one mainly made of resin or silica is used as shown in FIG. However, since the spherical spacers in the liquid crystal material 130 are easy to move, there are problems of a decrease in contrast due to the movement to the display portion and a nonuniform cell gap due to a nonuniform spacer distribution. In addition, when a spherical spacer is mixed in the sealing material 150, the substrate 110, the glass substrate 120, and the spacer 140 are in point contact, and there is a problem of damage due to stress concentration. Recently, the use of a spacer using a photosensitive resin instead of a spherical spacer has been studied. Since the spacer using the photosensitive resin can be formed on the substrate 110 by exposure / development processing, the spacer itself has a merit that it can be finely processed and accurately placed at a desired position, but is inferior in moisture resistance and strength. There is also a problem that the organic component of the liquid promotes the deterioration of the liquid crystal material. In order to solve these problems, Patent Document 1 (Japanese Patent Laid-Open No. 6-273773) discloses a liquid crystal display device using a spacer made of an inorganic insulator film such as a silicon oxide film or a silicon nitride film. However, when the vicinity of the wall-shaped spacer 141 made of a highly rigid inorganic insulator is bonded with the sealing material 150, as shown in FIGS. In other words, the uniformity of the cell gap is impaired. In order to solve this problem, in Patent Document 1 (Japanese Patent Laid-Open No. 6-273773), the sealing material 150 is disposed on both sides of the wall spacer 141 as shown in FIG. 8C.
JP-A-6-273773

  However, in the conventional structure, since the liquid crystal material 130 and the sealing material 150 are in direct contact with each other, the organic component contained in the sealing material 150 promotes deterioration of the liquid crystal material 130, Since the width is as wide as about 1 mm, there is a problem that the installation area becomes wide. In addition, as shown in FIG. 9, when the sealing portion is enlarged, the wall spacer 141 is formed by a semiconductor (or similar to semiconductor) process such as exposure, development, and etching, so that the wall surface shape is linear. Since the sealing material 150 is formed by an application process using a syringe or the like, the wall surface has a wavy shape. This means that the volume of the cell surrounded by the Si substrate 110, the glass substrate 120, and the sealing material 150 varies. In the case of a large-sized liquid crystal display device such as a direct-view type, there is no problem, but in the case of a liquid crystal display device with a small chip size such as a liquid crystal silicon (LCOS) or a high-temperature poly-Si panel, the liquid crystal material 130 Since the total amount is very small, variations in cell volume cannot be ignored. For this reason, there has been a problem in that the manufacturing process of the large-format liquid crystal display device cannot reduce the manufacturing cost and the part process of applying the sealing material, dropping the liquid crystal, and laminating the substrates, which is performed in order to prevent the yield reduction due to the foreign matter. . An object of the present invention is to solve these problems and provide a liquid crystal display device having excellent display quality.

  INDUSTRIAL APPLICABILITY The present invention provides an inorganic insulation as a spacer member for controlling a cell thickness as a means for providing a liquid crystal display device with excellent display quality at a low cost and with a precisely controlled substrate gap (cell gap). A body film is used, and a spacer is arranged outside the display pixel region. Further, as shown in FIG. 10, wall spacers 141 made of an inorganic insulator film are arranged and bonded so as to sandwich both sides of a sealing material 150 (adhesive) for bonding two opposing substrates together. Features. As the inorganic insulator film, a silicon oxide film, a silicon nitride film, a silicon carbide, a silicon carbide film containing hydrogen, an aluminum oxide, or the like and a laminated film thereof can be used.

  By using an inorganic insulator film as a spacer member, the inorganic insulator film in the display pixel can be patterned by a series of methods by exposure, development and etching, and the spacer can be disposed only outside the display pixel. The orientation characteristics of the film can be prevented from being adversely affected. Furthermore, the inorganic insulator film has high mechanical strength, and the film is not broken even when the substrate bonding is pressed, and a predetermined cell thickness can be maintained. By disposing wall spacers 141 made of an inorganic insulator film on both sides of the sealing material 150, walls made of an inorganic insulator film having high rigidity on both sides of the sealing material 150 even when the sealing material 150 contracts. Since the spacers 141 hold the glass substrate 120 evenly, the warp of the glass substrate 120 can be prevented. Further, since the wall-shaped spacer 141 made of the inner inorganic insulating film is in contact with the liquid crystal material 130, the wall surface shape is linear, and the volume of the cell surrounded by the Si substrate 110, the glass substrate 120, and the wall-shaped spacer 141 varies. In addition, since the sealing material 150 and the liquid crystal material 130 are not in direct contact with each other, the liquid crystal material 130 is not deteriorated by an organic component.

  Therefore, by using the present invention, a liquid crystal display device having a uniform cell gap thickness can be provided without adversely affecting the alignment characteristics of the liquid crystal, and a uniform display with high contrast can be achieved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Each of the embodiments described below is a preferable specific example of the present invention, and various technically preferable limitations are provided, but the technical scope of the present invention is limited to these embodiments. is not.

(First embodiment)
FIG. 1 is a top view of an LCOS device which is a kind of liquid crystal display device according to the first embodiment of the present invention. The cell of this embodiment includes a Si substrate 110 having a reflective electrode and a drive circuit on the surface of a pixel area of 14 mm × 18 mm and a chip area of 16 mm × 20 mm, and the Si substrate 110 on the surface of the Si substrate 110. A sealing material pattern 150 having a width of 1 mm formed along the peripheral edge, a wall-like spacer A142 having a width of 20 μm made of an inorganic material formed inside the sealing material pattern 150 and outside the pixel region, and the sealing A 20 μm wide wall spacer B 143 made of an inorganic material formed outside the material pattern 150, a glass substrate 120 having a transparent electrode on the surface, and the Si substrate 110 and the glass substrate 120 are attached with a gap of 2 μm. And a VA liquid crystal 131 injected into the cell. An ultraviolet curable adhesive was used as the sealing material, and SOG (Spin-On-Glass) was used as the wall spacer made of an inorganic material. None of the wall spacers made of an inorganic material need be continuous. By adopting such a configuration, the uniformity of the gap where the Si substrate 110 and the glass substrate 120 are bonded to each other can be suppressed to ± 5% in the plane, and the glass substrate 120 is not warped and a good image is obtained. The resulting LCOS device was obtained. In FIG. 1, one wall spacer A142 and one wall spacer B143 are shown, but two or more may be used. Further, by using a glass substrate instead of the Si substrate 110 and a transparent electrode instead of the reflective electrode, the same effect can be obtained even in a high-temperature Poly-Si panel.

(Second Embodiment)
FIG. 2 is a top view of an LCOS device which is a kind of liquid crystal display device according to the second embodiment of the present invention. The cell of this embodiment includes a Si substrate 110 having a reflective electrode and a drive circuit on the surface of a pixel area of 14 mm × 18 mm and a chip area of 16 mm × 20 mm, and the Si substrate 110 on the surface of the Si substrate 110. A sealing material pattern 150 having a width of 1 mm formed along the peripheral edge, a wall-like spacer A142 having a width of 20 μm made of an inorganic material formed inside the sealing material pattern 150 and outside the pixel region, and the sealing A wall spacer B143 having a width of 20 μm made of an inorganic material formed outside the material pattern 150, a glass substrate 120 having a transparent electrode on the surface, and a gap (cell gap) of 2 μm between the Si substrate 110 and the glass substrate 120. The cell has a laminated cell and a VA liquid crystal 131 injected into the cell. An ultraviolet curable adhesive was used as the sealing material, and SOG (Spin-On-Glass) was used as the wall spacer made of an inorganic material. The wall-shaped spacer B142 made of an inorganic material formed outside the sealing material pattern 150 is a closed curve including the cells. By adopting such a configuration, the uniformity of the gap between the Si substrate 110 and the glass substrate 120 can be suppressed to ± 5% in the surface, the glass substrate 120 is not warped, and the sealing is performed. Since the cell was surrounded by the wall-like spacer B142 made of an inorganic material superior in moisture resistance to the material 150, a good image was obtained and a highly reliable LCOS device was obtained. In FIG. 2, one wall spacer A142 and one wall spacer B143 are shown, but two or more may be used. Further, by using a glass substrate instead of the Si substrate 110 and a transparent electrode instead of the reflective electrode, the same effect can be obtained even in a high-temperature Poly-Si panel.

(Third embodiment)
FIG. 3 is a top view of an LCOS device which is a kind of liquid crystal display device according to the third embodiment of the present invention. The cell of this embodiment includes a Si substrate 110 having a reflective electrode and a drive circuit on the surface of a pixel area of 14 mm × 18 mm and a chip area of 16 mm × 20 mm, and the Si substrate 110 on the surface of the Si substrate 110. A sealing material pattern 150 having a width of 1 mm formed along the peripheral edge, a wall-like spacer A142 having a width of 20 μm made of an inorganic material formed inside the sealing material pattern 150 and outside the pixel region, and the sealing A wall spacer B143 having a width of 20 μm made of an inorganic material formed outside the material pattern 150, a glass substrate 120 having a transparent electrode on the surface, and a gap (cell gap) of 2 μm between the Si substrate 110 and the glass substrate 120. The cell has a laminated cell and a VA liquid crystal 131 injected into the cell. An ultraviolet curable adhesive was used as the sealing material, and SOG (Spin-On-Glass) was used as the wall spacer made of an inorganic material. The wall spacer A142 made of an inorganic material formed inside the sealing material pattern 150 and outside the pixel region is a closed curve including the cells. By adopting such a configuration, the uniformity of the gap between the Si substrate 110 and the glass substrate 120 can be suppressed to ± 5% in the plane, the glass substrate 120 is not warped, and the cell However, since the end face is linear and surrounded by the wall spacer A142 with high positional accuracy, and the cell gap is also defined by the wall spacer A142 and wall spacer B143 with high dimensional accuracy, the accuracy of the cell volume is also high. An LCOS device was obtained that was high and provided good images. In FIG. 3, one wall spacer A142 and one wall spacer B143 are shown, but two or more each may be used. Further, by using a glass substrate instead of the Si substrate 110 and a transparent electrode instead of the reflective electrode, the same effect can be obtained even in a high-temperature Poly-Si panel.

(Fourth embodiment)
FIG. 4 is a top view of an LCOS device which is a kind of liquid crystal display device according to the fourth embodiment of the present invention. The cell of this embodiment includes a Si substrate 110 having a reflective electrode and a drive circuit on the surface of a pixel area of 14 mm × 18 mm and a chip area of 16 mm × 20 mm, and the Si substrate 110 on the surface of the Si substrate 110. A sealing material pattern 150 having a width of 1 mm formed along the peripheral edge, a wall-like spacer A142 having a width of 20 μm made of an inorganic material formed inside the sealing material pattern 150 and outside the pixel region, and the sealing A wall spacer B143 having a width of 20 μm made of an inorganic material formed outside the material pattern 150, a glass substrate 120 having a transparent electrode on the surface, and a gap (cell gap) of 2 μm between the Si substrate 110 and the glass substrate 120. The cell has a laminated cell and a VA liquid crystal 131 injected into the cell. An ultraviolet curable adhesive was used as the sealing material, and SOG (Spin-On-Glass) was used as the wall spacer made of an inorganic material. A wall-shaped spacer A142 made of an inorganic material formed inside the sealing material pattern 150 and outside the pixel region, and a wall-shaped spacer B143 made of an inorganic material formed outside the sealing material pattern 150 and having a width of 20 μm, Both are closed curves containing the cells. By adopting such a configuration, the uniformity of the gap between the Si substrate 110 and the glass substrate 120 can be suppressed to ± 5% in the plane, the glass substrate 120 is not warped, and the cell However, since the end face is linear and surrounded by the wall spacer A142 with high positional accuracy, and the cell gap is also defined by the wall spacer A142 and wall spacer B143 with high dimensional accuracy, the accuracy of the cell volume is also high. Since the cells are surrounded by the wall spacers A142 and B142 made of an inorganic material that is high and has higher moisture resistance than the sealing material 150, a good image is obtained and a highly reliable LCOS device is obtained. . In FIG. 4, one wall spacer A142 and one wall spacer B143 are shown, but two or more each may be used. Further, by using a glass substrate instead of the Si substrate 110 and a transparent electrode instead of the reflective electrode, the same effect can be obtained even in a high-temperature Poly-Si panel.

(Fifth embodiment)
FIG. 5 is a diagram showing a method of manufacturing an LCOS device which is a kind of liquid crystal display device according to the fifth embodiment of the present invention. First, as shown in FIG. 5A, a Si substrate 110 having a reflective electrode and a drive circuit on its surface is prepared. Next, as shown in FIG. 5B, an inorganic material to be a wall spacer is formed. The inorganic material is preferably SOG which can be industrially formed by coating and whose film thickness can be controlled by the rotation speed of the spinner, but may be formed by vapor deposition or sputtering. In this embodiment, SOG for thick film was applied at 2000 rpm, prebaked at 250 ° C. for 3 minutes, and cured at 400 ° C. for 30 minutes to form a 2 μm SOG film. Next, as shown in FIG. 5C, a wall spacer A142 and a wall spacer B143 having a width of 20 μm are formed outside the pixel region by resist coating / exposure / development / etching. Etching was performed by a dry etching apparatus. Next, as shown in FIG. 5D, a sealing material 150 is applied between the wall spacer A142 and the wall spacer B143 by a dispenser. Subsequently, as shown in FIG. 5 (e), a glass substrate 120 was attached to the Si substrate 110, and cured and adhered by UV irradiation at 100 mW / cm 2 for 15 seconds and heat treatment at 120 ° C. for 60 minutes. Next, as shown in FIG. 5 (f), VA liquid crystal 151 is injected from the inlet 151, and then the liquid crystal is sealed with a sealing material A152 as shown in FIG. 5 (g). By forming the wall spacer A142 and the wall spacer B143 with an inorganic insulator film (SOG in this embodiment) having high mechanical strength, the gap (cell gap) can be accurately controlled. By forming the A 142 and the wall-like spacer B 143 as a closed curve that completely surrounds the pixel region 160, the sealing material 150 and the VA liquid crystal 131 are prevented from coming into direct contact with each other, and the organic components remaining in the sealing material 150 are prevented. The deterioration of the VA liquid crystal 131 can be prevented and the moisture resistance can be improved. By discontinuously forming the wall spacer B143, the extra sealing material 150 is released to the area outside the wall spacer B143, and the pixel area It is possible to prevent display defects and deterioration of the liquid crystal from protruding to 160. When the application amount of the sealing material 150 can be controlled appropriately, the wall-like spacer B 143 can also be formed as a closed curve that completely surrounds the pixel region 160 to improve moisture resistance. Further, by using a glass substrate instead of the Si substrate 110 and a transparent electrode instead of the reflective electrode, the same effect can be obtained even in a high-temperature Poly-Si panel.

(Sixth embodiment)
FIG. 6 is a diagram showing a method for manufacturing an LCOS device which is a kind of liquid crystal display device according to the sixth embodiment of the present invention. First, as shown in FIG. 6A, a Si substrate 110 having a reflective electrode and a drive circuit on its surface is prepared. Next, as shown in FIG. 6B, an inorganic material to be a wall spacer is formed. The inorganic material is preferably SOG which can be industrially formed by coating and whose film thickness can be controlled by the rotation speed of the spinner, but may be formed by vapor deposition or sputtering. In this example, SOG for thick film was applied at 2000 rpm, prebaked at 250 ° C. for 3 minutes, and cured at 400 ° C. for 30 minutes to form a 2 μm SOG film. Next, as shown in FIG. 6C, a wall spacer A142 and a wall spacer B143 having a width of 20 μm are formed outside the pixel region by resist coating / exposure / development / etching. Etching was performed by a dry etching apparatus. Next, as shown in FIG. 6D, a sealing material 150 is applied between the wall spacer A142 and the wall spacer B143 by a dispenser, and vertical gradient liquid crystal (VA liquid crystal) is continuously dropped. . Subsequently, as shown in FIG. 6 (e), the glass substrate 120 was attached in the same apparatus, and cured and adhered by UV irradiation at 100 mW / cm 2 for 15 seconds and heat treatment at 120 ° C. for 60 minutes. At this time, it is possible to control the gap (cell gap) with high accuracy by forming the wall spacer A 142 and the wall spacer B 143 with an inorganic insulator film (SOG in this embodiment) having high mechanical strength. In addition, by forming the wall spacer A142 as a closed curve that completely surrounds the pixel region 160, the sealing material 150 and the VA liquid crystal 131 are prevented from coming into direct contact with each other, and organic components remaining in the sealing material 150 are prevented from being in contact with each other. The deterioration of the VA liquid crystal 131 can be prevented, and the wall-shaped spacer B143 is discontinuously formed, so that the excess sealing material 150 escapes to a region outside the wall-shaped spacer B143 and protrudes into the pixel region 160. It is possible to prevent display defects and liquid crystal deterioration. When the application amount of the sealing material 150 can be controlled appropriately, the wall-like spacer B 143 can also be formed as a closed curve that completely surrounds the pixel region 160 to improve moisture resistance. Although not shown in the figure, all the steps up to here are performed in a wafer state (large substrate state), and then divided into chips by dicing, thereby reducing the cost compared to performing bonding for each chip. Thus, the liquid crystal display device can be manufactured. Further, by using a glass substrate instead of the Si substrate 110 and a transparent electrode instead of the reflective electrode, the same effect can be obtained even in a high-temperature Poly-Si panel.

It is the top view and sectional drawing of the LCOS device which are 1 type of the liquid crystal display device of 1st Embodiment in this invention. It is the top view and sectional drawing of the LCOS device which are 1 type of the liquid crystal display device of 2nd Embodiment in this invention. It is the top view and sectional drawing of the LCOS device which are 1 type of the liquid crystal display device of 3rd Embodiment in this invention. It is the top view and sectional drawing of the LCOS device which are 1 type of the liquid crystal display device of 4th Embodiment in this invention. It is a figure explaining the manufacturing method of the LCOS device which is 1 type of the liquid crystal display device of 5th Embodiment in this invention. It is a figure explaining the manufacturing method of the LCOS device which is 1 type of the liquid crystal display device of 6th Embodiment in this invention. It is a conceptual sectional view of a conventional reflective liquid crystal display device. It is a conceptual diagram of the curvature of the glass substrate accompanying the shrinkage | contraction of the sealing material of a conventional structure. It is an enlarged view of the sealing part of a conventional structure. It is an enlarged view of the sealing part in this invention.

Explanation of symbols

01 liquid crystal display device 110 Si substrate 120 glass substrate 130 liquid crystal material 131 VA liquid crystal 140 spacer 141 wall spacer 142 wall spacer A
143 Wall spacer B
150 Sealant 151 Inlet 152 Sealant A
160 pixel area

Claims (10)

A first substrate having a pixel region in which a pixel electrode is formed; a second substrate having a second electrode; and a wall spacer and a seal between the first substrate and the second substrate. In the liquid crystal display device provided with the agent pattern,
The sealing material pattern is formed outside the pixel region, and the wall-shaped spacer is formed on the sealing material pattern on the pixel region side with respect to the sealing material pattern and outside the pixel region. On the other hand, a liquid crystal display device comprising an inorganic material formed on both the pixel region and the region opposite to the pixel region.   The liquid crystal display device according to claim 1, wherein a plurality of the pixel electrodes are arranged in a matrix.   The liquid crystal display device according to claim 1, wherein the wall-shaped spacers formed in a region opposite to the pixel region with respect to the sealing material pattern are discontinuously arranged.   The wall-like spacers formed on the pixel region side and on the outer side of the pixel region with respect to the sealing material pattern are continuously arranged, and the region closer to the pixel region than the arranged region The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a closed space.   The liquid crystal display device according to claim 4, wherein the wall-like spacers formed in a region opposite to the pixel region with respect to the sealing material pattern are continuously arranged.   The liquid crystal display device according to claim 1, wherein the pixel electrode is a reflective electrode.   The wall-like spacer formed on the pixel region side and outside the pixel region with respect to the sealing material pattern, and the region opposite to the pixel region with respect to the sealing material pattern. The liquid crystal display device according to claim 1, wherein the wall spacers are made of the same material.   Forming a first electrode on the surface of the first substrate, forming a plurality of wall spacers made of an inorganic material on the surface of the first substrate and outside the pixel region; Forming a second electrode on the surface of the second substrate, dividing the first substrate and the second substrate into chips by dicing, and forming a peripheral portion of the divided first substrate. Forming a sealing material pattern so as to be sandwiched between the plurality of wall-shaped spacers, bonding the divided second substrate and the divided first substrate, and the inside of the sealing material pattern And a step of injecting a liquid crystal material into the pixel region and sealing the liquid crystal display device.   Forming a first electrode on the surface of the first substrate, forming a plurality of wall spacers made of an inorganic material on the surface of the first substrate and outside the pixel region; A step of forming a second electrode on the surface of the second substrate, and a plurality of wall-shaped spacers on the surface of the first substrate and at the peripheral edge of the first substrate and made of the inorganic material Forming a sealing material pattern in a form, dropping a liquid crystal material on the pixel region, and bonding the second substrate and the first substrate with a predetermined gap. A method for manufacturing a liquid crystal display device, comprising: dividing by dicing after performing the above steps.   When the first electrode is formed on the surface of the first substrate, a transparent and insulating film is formed on the surface of the first electrode, and the film is formed in the step of forming the wall spacer. 10. The method for manufacturing a liquid crystal display device according to claim 8, wherein the liquid crystal display device is used as a stopper.

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