JP3780764B2 - Liquid crystal device and electronic apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high picture quality and to improve the manufacturing yield by providing thick parts having a thickness thicker than those of the pixel electrode central parts on the periphery of the respective pixel electrodes so as to prevent the switching elements from being broken in a rubbing treatment process and so as to eliminate the generation of defective pixels. SOLUTION: Many pixel electrodes 6, which are connected to straight linear wiring parts 7 of data lines via thin film diode(TFD) driving elements 10, are arranged in a matrix within a liquid crystal panel region. Besides, a thick part 8 protruding in a direction toward the C corner and having a thickness thicker than that of the pixel electrode central part is provided on the D corner of the pixel electrode 6. Thereby in the case rubbing treatment is carried out from the upper right to the lower left, depicted in the figure, to 45 deg. arrow L direction, the thick part 8 displays a function of a protecting wall for the TFD driving element 10. For example, the thick part 8 arranged on a pixel electrode a-2 protects the TFD driving element 10, placed a step lower, on the A corner of a pixel electrode b-2.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a liquid crystal device, and in particular, prevents the occurrence of defects in the liquid crystal device due to destruction of a switching element in a rubbing process for aligning liquid crystal molecules.
[0002]
[Prior art]
In recent years, large-capacity matrix liquid crystal devices have been used for personal computer displays and the like. Among them, active matrix type liquid crystal display devices in which a thin film element having a switching action is introduced between a pixel electrode and a signal wiring are mainly used as liquid crystal display devices with high image quality and large capacity. Typical examples of switching elements of an active matrix liquid crystal display device include a thin film diode (hereinafter abbreviated as TFD) and a thin film transistor (hereinafter abbreviated as TFT). Using the function of the switching element, it is possible to drive a large number of pixels arranged in a matrix to display an arbitrary character or figure.
[0003]
On the other hand, twisted nematic (TN) liquid crystal display devices that are widely used today have a large viewing angle dependency, and it is necessary to balance the viewing angle in the vertical and horizontal directions of the display characteristics. It is necessary to let
[0004]
The alignment direction of the liquid crystal molecules is easily regulated by the surface state of the substrate, but the liquid crystal molecules cannot be aligned in a predetermined direction because there is a degree of freedom in the alignment direction of the liquid crystal molecules simply by aligning them in parallel. . In order to align the liquid crystal molecules in a specific direction, means for physically regulating the major axis direction of the liquid crystal molecules by providing an adherend or groove having alignment in the specific direction on the substrate surface is employed. As the main means, a means for applying an orientation film such as a polyimide resin or a means for imparting orientation by scratching the surface of the orientation film in a specific direction is employed. Examples of means for imparting directionality by scratching the alignment film include oblique vapor deposition and rubbing. The oblique vapor deposition method has disadvantages such as low production efficiency and insufficient image contrast, so that the rubbing method is widely used. Usually, as the rubbing method, a rubbing rubbing method in which an alignment film such as a polyimide resin is rubbed with a cloth or a rotating rubbing method in which a rubbing method with a brush having a diameter of 10 to 20 μm is used is put into practical use.
[0005]
Normally, in the TN liquid crystal display device, as shown in FIG. 1A, the alignment film on the element substrate 1 side is rubbed in the direction of 45 degrees with respect to each square pixel, while the counter substrate 2 side The alignment film is further rubbed in the direction of 135 degrees twisted by 90 degrees. In this way, the liquid crystal material is sealed between the alignment films of the two substrates in a state where the rubbing direction of the alignment film is twisted 90 degrees, and the liquid crystal material is kept in a twisted state.
[0006]
The rubbing direction is not limited to the direction shown in FIG. 1A, and may be the direction shown in FIG. Also in this case, the rubbing direction of the alignment film on the element substrate side and the alignment film on the counter substrate side is twisted by 90 degrees.
[0007]
However, in the switching element structure composed of a thin film laminate, the thin film of the switching element part is destroyed due to foreign matters such as the tip of the brush during the rubbing process or dust introduced into the rubbing process, resulting in an element failure, and dot pixel defects. Such a problem is that display is impossible and the production yield of a product as a liquid crystal device is lowered.
[0008]
An SEM observation of the vicinity of the switching element portion of the pixel electrode exhibiting such a point defect revealed that there was an oblique scratch in the switching element portion, and the thin film stack structure of the switching element was destroyed, causing an insulation failure. It was. It was found that the scratch was inclined 45 degrees with respect to the square pixel electrode and coincided with the rubbing direction. When the rubbing brush when the scratch was generated was observed, it was observed that the tip of the brush having a diameter of about 10 to 20 μm was sharply cut or foreign matter adhered to the tip.
[0009]
In order to prevent scratches generated during the rubbing process, the applicant of the present invention previously formed a portion having a thickness equal to or greater than the film thickness for forming the switching element when forming the switching element. There have been proposed a method (see Japanese Patent Application Laid-Open No. 61-165729), a method of arranging electrodes constituting the switching element at an angle of 45 degrees along the rubbing direction (see Japanese Patent Application Laid-Open No. 6-35005), and the like. However, even with these methods, there is no means for securing the visual field area of the pixel and preventing the increase in the manufacturing process and exhibiting the effect of preventing effective scratches. The present invention is a further improvement of these methods.
[0010]
[Problems to be solved by the invention]
That is, an object of the present invention is to provide means for preventing scratches generated when a liquid crystal device having a switching element is subjected to an alignment process by a rubbing process, and is an effective means for protecting the switching element with respect to the alignment direction. And to provide a method that does not place a burden on the manufacturing process.
[0011]
[Means for Solving the Problems]
The present invention has been made to eliminate the above-described drawbacks, and includes a scanning line or a data line, a plurality of switching elements connected to the substrate, a pixel electrode, and an element substrate formed with an alignment film, In a liquid crystal device having a counter substrate disposed opposite to the element substrate and having a counter electrode and an alignment film formed on the substrate and having a liquid crystal material between the two substrates, each pixel electrode A means for providing a thick part at the peripheral part thicker than the thickness of the central part of the pixel electrode was adopted.
[0012]
In this way, by providing a thicker portion at a specific position of the pixel electrode that is thicker than the thickness of the central portion of the pixel electrode, the tip of the rubbing brush passes through each switching element portion in the rubbing step. The brush reduces the impact of the brush on the switching element part, and prevents foreign matter such as dust from entering the switching element part to prevent scratches.
[0013]
In the present invention, since the structure of the thick part has a thin film laminated structure having the same structure as that of the switching element at least in part, the thick part can be formed at the same time when the switching element is formed. The number of processes does not increase and high productivity can be maintained.
[0014]
First, the structure of the liquid crystal display panel of the liquid crystal device that is the subject of the present invention will be described.
[0015]
FIG. 2 is a partial plan view partially showing a plan view of an embodiment showing an outline of an active matrix liquid crystal display panel using a TFD driving element as a switching element according to the present invention. In the figure, an element substrate 1 and a counter substrate 2 are arranged to face each other and are bonded to each other by a seal portion 4. The distance between the substrates is defined by bead-like spacers having a minute diameter that are dispersed and arranged between the substrates, and are held at about 5 μm, for example. A liquid crystal injection port 3 exposed to the outside of the panel is provided in a part of the seal portion 4, and the liquid crystal surrounded by the seal portion 4 is injected from the liquid crystal injection port 3 and sealed in the sealing portion 5.
[0016]
In the region of the counter substrate 2 that protrudes from the element substrate 1 (on the right side in the figure), for example, when the counter electrode on the counter substrate side is used as a scanning line, a scanning side driving IC 50a that supplies a scanning signal is disposed. . Similarly, the data side driving IC 50b is also arranged on the element substrate side (the back side of the substrate in the figure). Reference numeral 51 denotes an input terminal for supplying a signal from the outside to the driving IC.
[0017]
A large number of rectangular pixel electrodes 6 are arranged in a matrix on the element substrate 1 and are connected to the wiring section 7 via switching elements described in detail later. A transparent electrode made of indium tin oxide (hereinafter abbreviated as ITO) is formed in a stripe shape in the left-right direction on the counter substrate 2 facing the element substrate 1. Control signals are sent to individual pixel electrodes and transparent electrodes, and predetermined pixels are displayed as dots, whereby characters and figures are recognized as a whole display device. An alignment film such as polyimide is applied to the surface of the element substrate 1 and the counter substrate 2 facing each other. The alignment film is rubbed to give directionality, and the two substrates are bonded. When the arrangement as shown in FIG. 2 is adopted, for example, the rubbing direction of the alignment film on the element substrate side is a 45 degree direction from the upper right to the lower left of the drawing, and the rubbing direction of the alignment film on the opposite substrate is the upper left of the drawing. Are orthogonal to each other in the direction of 45 degrees from the right to the lower right (see FIG. 1A).
[0018]
In addition, although not shown, polarizing plates are attached to the surfaces of the element substrate 1 and the counter substrate 2 opposite to the surfaces facing each other. In addition, a flexible substrate connected to the input terminal 51, a light source disposed on the back of the panel in the case of a transmissive panel, and the like, and a circuit for generating a signal to be supplied to the driving IC 50 and a power supply circuit are mounted. These components including a control board called a control box and a panel are accommodated in a case to constitute a liquid crystal device.
[0019]
Next, switching elements used in the liquid crystal display panel will be described.
[0020]
FIG. 3 and FIG. 4 illustrate the enlarged vicinity of one pixel electrode of the liquid crystal display panel. 4 is a cross-sectional view taken along line AA ′ of FIG. In this example, the left corner of the peripheral edge of the pixel electrode 6 is connected to the wiring part 7 via a TFD driving element 10 which is a two-terminal nonlinear element serving as a switching element. The TFD driving element 10 in the case of FIG. 3 has a loose back-to-back structure. That is, the first TFD driving element 10a and the second TFD driving element 10b are configured to be connected in series with opposite polarities.
[0021]
3 and 4, the TFD driving element 10 is composed of two elements 10a and 10b. The first TFD driving element 10a has an insulating film 31 formed on the element substrate 1 as a base layer, and a top layer. The first metal film 12 made of tantalum or the like, the insulating film 14 made of anodic oxide film or the like, and the second metal film 16a made of chromium or the like are sequentially formed. On the other hand, the second TFD driving element 10b is composed of an insulating film 31 formed on the element substrate 1 as a base layer, a first metal film 12 made of tantalum or the like sequentially formed thereon, an anodic oxide film, or the like. The second metal film 16b is made of chromium or the like isolated from the insulating film 14 and the second metal film 16a. The first metal film 12 has a thickness of about 150 nm, the insulating film 14 has a thickness of about 20-30 nm, and the second metal film 16 has a thickness of about 80-100 nm.
[0022]
Here, the second metal film 16 a of the first TFD driving element 10 a is connected to the second metal film 16 on the wiring portion 7 formed on the element substrate 1. Furthermore, the second metal film 16b of the second TFD driving element secures a contact area with the pixel electrode 15 and prevents the corrosion cutting due to the wraparound of the etching liquid when formed by etching, as shown in FIG. The pixel electrode 6 is arranged in such a manner that it partially overlaps the corner of the pixel electrode 6.
[0023]
Now, for example, when the alignment film surface of the element substrate coated with the alignment film is rubbed in the direction of the arrow L from the upper right to the lower left in FIG. 3, the tip of the rubbing brush directly rubs the TFD driving element 10, and the brush If the tip of the tape is sharply cut or if a foreign object is caught in the tip of the brush, the TFD drive element 10 made of a thin film is easily scratched and the thin film is destroyed, resulting in an insulation failure. As a result, it loses its function.
[0024]
As another example of the TFD driving element as the switching element, an example of a so-called cross structure will be described with reference to FIGS. 5 and 6, the TFD driving element 20 includes a first metal film 22 made of tantalum or the like formed in order on an insulating film 31 formed on the element substrate 1, an anodic oxide film, and the like. A TFD structure including the insulating film 24 and the second metal film 26 made of chromium or the like is formed. The first metal film 22 is connected to the first metal film of the wiring portion 7 formed on the element substrate 1, and the second metal film 26 is partially connected to the corner portion of the pixel electrode 6. Yes. As in the case of the back-to-back structure described above, the thickness of the first metal film 22 is about 150 nm, the thickness of the insulating film 24 is about 50 nm, and the thickness of the second metal film 26. Is about 80-100 nm. Even in such a structure, since the thin film laminated structure is used, the state of damage to the element during the rubbing process is the same as in the case of the back-to-back element structure described above.
[0025]
In the present invention, in order to prevent scratches received by the TFD drive element part during the rubbing process as described above, a thicker part thicker than the center part of the pixel electrode is provided at the peripheral part of the pixel electrode, and the brush is used. The impact received by the TFD drive element unit is reduced, and foreign matter that the brush is involved in is prevented from being brought into the TFD drive element unit.
[0026]
The thick portion needs to be provided in consideration of the rubbing direction at the peripheral portion of the pixel electrode so as not to decrease the aperture ratio of the pixel electrode. When the alignment film surface is rubbed in a direction of 45 degrees with respect to each pixel electrode, the center of the pixel electrode is arranged so that the brush acts as a protective wall of the TFD drive element unit immediately before entering the TFD drive element unit. It is sufficient that there is a thick part thicker than the part. That is, it is only necessary that the thick part thicker than the central part of the pixel electrode is on the extended line in the rubbing direction passing through the TFD driving element.
[0027]
Such a thick portion may be provided in a frame shape along the entire periphery of the pixel electrode, but it also hinders the rubbing effect, so it is effective to provide it partially on the periphery of the pixel electrode. is there. In consideration of simultaneously rubbing the entire area of the panel having a plurality of pixel electrodes coated with an alignment film, it is effective to dispose the thick portion using the corners of each pixel electrode.
[0028]
The thick portion may be in the pixel electrode portion, a part thereof may overlap the pixel electrode, or may be disposed outside the pixel electrode.
[0029]
It is sufficient that the width (w) of the thick part is about 2 to 3 μm. In addition, the length (d) may be the entire area of one side of the pixel electrode, and the length (d) may be about one third to one third of one side of the pixel electrode in consideration of the size of the TFD driving element and the rubbing direction. It is enough.
[0030]
Further, if the thickness of the thick part is thicker than the central part of the pixel electrode, the effect of preventing scratches can be exhibited. In consideration of the manufacturing process, if the thick portion is formed with the same structure at the same time when forming the TFD driving element, it is efficient without increasing the process. Furthermore, if it is allowed to increase the number of steps, it is possible to form the thick portion with an insulating resin other than the material forming the TFD driving element.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 7 is a plan view showing an embodiment of an element substrate of a liquid crystal panel used in the liquid crystal device according to the present invention, and a part of the element substrate 1 of one liquid crystal display panel shown in FIG. It is an enlarged view. In this embodiment, an example is shown in which the switching element uses a TFD driving element having a back-to-back structure. In FIG. 7, a large number of pixel electrodes 6 connected to the wiring section 7 via the TFD driving element 10 are arranged in a matrix in one liquid crystal panel region. For ease of explanation, the pixel electrodes 6 are a-1, a-2, a-3,..., B-1, b-2, b-3. The four corners of one pixel electrode are positioned as A, B, C, and D. In FIG. 7, the TFD driving element 10 is arranged at the corner A of the pixel electrode 6.
[0032]
When a panel having an alignment film applied on the pixel electrode is rubbed in the direction of an arrow L of 45 degrees from the upper right to the lower left of the paper in the rubbing process, the D corner of the pixel electrode 6 is directed toward the C corner. Providing the overhanging thick portion 8 thicker than the center portion of the pixel electrode has a function as a protective wall for the TFD drive element 10. In FIG. 7, the TFD drive element 10 is arranged at the corner A, and there are two corners adjacent to each other, the B corner and the D corner. Among these, the D corner is an adjacent corner in the direction along the wiring portion 7. That is, in the example of FIG. 7, the thick portion 8 is along the wiring portion 7 among the two adjacent corner portions B and D adjacent to the corner portion of the pixel electrode 6 to which the switching element 10 is connected. It suffices if it is in the adjacent corner portion D in the other direction. If the thick portion 8 is arranged at such a position, for example, the thick portion 8 provided at a-2 protects the TFD drive element 10 at the A corner of b-2 below one row. Similarly, the thick portion 8 provided at a-3 can protect the TFD drive element 10 at the A corner of b-3 below one row. Thus, the thick portion 8 may be disposed on the extended line of the line L in the rubbing direction passing through the TFD drive element 10.
[0033]
Here, the corner portion A has the TFD driving element 10, and the second metal film 16 b of the second TFD driving element 10 b overlaps a part of the pixel electrode 6, and is thicker than the central portion of the pixel electrode 6. Therefore, since it has a certain degree of protective function for the TFD drive element 10, it is not necessary to dare to provide a thick part, but the ITO film 15 forming the pixel electrode 6 and the second metal in FIG. The structure of the first metal film / second metal film / pixel electrode may be formed by leaving a pattern of the first metal film formed simultaneously with the first metal film below the structure where the film 16b overlaps. .
[0034]
The width (w) of the thick portion 8 may be about 2 to 3 μm. The length (d) of the thick part 8 is not particularly limited, and it is sufficient that the TFD drive element 10 is hidden from the brush by the thick part 8 when rubbing in the direction of 45 degrees. Accordingly, it is only necessary to appropriately determine 1/3 to 1/6 of the length of one side of one pixel electrode.
[0035]
Next, a manufacturing method for manufacturing the element substrate of this embodiment will be described.
[0036]
A light-transmitting element substrate base material having a large area, such as glass, is prepared as a material, and a plurality of liquid crystal panel regions are formed on the element substrate base material.
[0037]
First, a tantalum film having a thickness of about 100 nm is formed on the element substrate base material by sputtering as a thin film forming means, and then a thermal oxidation is performed to form a tantalum oxide insulating film 31 serving as a base layer. This underlayer has a function of improving the adhesion between the element substrate 1 and a tantalum film which is a constituent element of a TFD driving element described later. Note that in the case where impurity diffusion into the tantalum film does not cause a problem, the formation of the insulating film can be omitted.
[0038]
On this insulating film 31, a tantalum alloy film containing 0.1 to 6 atomic% of tungsten and serving as the first metal film 12 of the wiring portion 7 and the TFD driving element 10 is formed by sputtering to a thickness of about 150 nm. . Next, patterning is performed by photoetching as shown in FIG. 3 in an enlarged manner, and a pattern to be the first metal film 12 of the wiring portion 7 and the TFD driving element 10 is formed in a predetermined shape. The width of the wiring part 7 is approximately 6 to 10 μm, and the width of the first metal film 12 of the TFD driving element 10 is approximately 2 to 3 μm. At this time, the tantalum pattern is once connected so that the wiring portion 7 and the tantalum film of the TFD driving element 10 are once connected so that the tantalum alloy film of the wiring portion 7 and the TFD driving element 10 is simultaneously anodized in an anodic oxidation process described later. 12a is formed (see b-1 in FIG. 7).
[0039]
At this time, a tantalum film pattern is also formed at the position of the corner D of the peripheral edge of each pixel electrode 6 as shown in FIG. The width (w) of the tantalum pattern is about 2 to 3 μm, and the length (d) is about 25 μm when it is a quarter of the length of one side of one pixel electrode, for example. This pattern becomes the thick portion 8 that protects the TFD driving element 10 in the rubbing process. This tantalum pattern is formed separately from the wiring portion 7 and the TFD driving element 10. However, in the anodic oxidation process described later, the tantalum pattern is simultaneously anodized on the wiring portion 7, the TFD driving element 10 and the tantalum alloy film at the D corner. In order to form a film, a pattern 12b is formed so as to once connect the wiring portion 7 and the tantalum alloy film at the D corner (see b-1 in FIG. 7).
[0040]
Further, a tantalum pattern may be left at a position where the pixel electrode 6 and the second metal film 16b (chrome film) overlap (see FIG. 14 described later).
[0041]
Next, each tantalum pattern is anodized to form a tantalum oxide film to be an insulating film 14 on the surface of each tantalum pattern with a thickness of about 20 to 30 nm.
[0042]
Thereafter, as shown in FIGS. 3 and 4, a chromium film serving as the second metal film 16a is connected to the insulating film 14 formed on the first TFD driving element 10a from the wiring portion 7 so as to partially overlap. Is formed to a thickness of about 80 to 100 nm by sputtering.
[0043]
At the same time, a chromium film serving as the second metal film 16b extending to the corner of the pixel electrode 6 is formed so as to partially overlap the insulating film 14 formed on the second TFD driving element 10b. It is formed by sputtering to a thickness of about ˜100 nm.
[0044]
At the same time, a chromium film is also formed by sputtering to a thickness of about 80 to 100 nm on the insulating film 14 on the surface of the tantalum pattern formed at the D corner of the pixel electrode 6 shown in FIG.
[0045]
Next, the tantalum patterns 12a and 12b left so that the wiring portion, the driving element portion, and the D corner portion are connected for anodic oxidation are removed by etching, and the wiring portion, the driving element portion, and the D corner portion are separated.
[0046]
Finally, the pixel electrode 6 is formed so as to partially overlap the second metal film 16b of the second TFD driving element 10b. As the pixel electrode 6, an ITO film or the like is formed to a thickness of about 50 nm. At the same time, the ITO film 15 is also formed on the tantalum pattern formed at the D corner of the pixel electrode 6 shown in FIG. Thus, the thick portion 8 as shown in cross section in FIG. 8 is formed at the position of the D corner which is the adjacent corner in the direction along the wiring portion 7 of the pixel electrode 6 shown in FIG. It is formed with the same thin film laminated structure. FIG. 8 is a diagram showing a cross-sectional structure along the line XX ′ shown in FIG.
[0047]
After forming the wiring part 7, the thick part 8, the TFD driving element 10 and the pixel electrode 6 on the element substrate as described above, a polyimide resin is applied on the element substrate, and the rectangular pixel electrode 6 is applied. The element substrate 1 of the liquid crystal display panel used in the present invention is rubbed in a 45 degree direction.
[0048]
On the other hand, after forming a transparent counter electrode corresponding to each pixel electrode on the counter substrate 2, a polyimide resin is applied and a rubbing process is performed in a direction twisted 90 degrees from the rubbing direction of the element substrate. The counter substrate 2 of the liquid crystal display panel used in the above is used. FIG. 9 shows a state in which the element substrate 1 and the counter substrate 2 thus obtained are bonded.
The alignment film 9 is on the surface in contact with the pixel electrode 6 inside each substrate.
[0049]
FIG. 10 shows another embodiment of the present invention. In the pattern of FIG. 10, the thick portion 8 is arranged at the D corner of the pixel electrode 6 and has a branching portion 8 a toward the A corner where the TFD driving element 10 is present. In this case, when a foreign matter is caught in the rubbing process, the foreign matter is captured at the corner portion 8c of the branching portion. The length of the thick portion 8 is set to a length sufficient to protect the TFD drive element 10 in the rubbing direction. On the other hand, the length of the branching portion 8a needs to be very small so that the corner portion 8c is formed.
[0050]
FIG. 11 shows another embodiment of the present invention. In the pattern of FIG. 11, the thick portion 8 is arranged at the C corner of the pixel electrode 6 that forms a diagonal with the TFD drive element 10, and has branch portions 8 a and 8 b toward the B corner and the D corner. It is composed. In this case, when the rubbing direction is the direction M from the upper left to the lower right in FIG. 11, it is effective to protect the TFD driving element 10 on the diagonal line (see FIG. 1B).
[0051]
FIG. 12 shows another embodiment of the present invention. In the pattern of FIG. 12, the thick portions 8 are arranged at the C corner and the D corner of the pixel electrode 6. Further, the thick portion 8 at the C corner is provided with two branch portions 8a and 8b, and the thick portion 8 at the D corner is provided with one branch portion 8a. According to this embodiment, there is an advantage that the rubbing direction can correspond to both the arrow L direction and the arrow M direction.
[0052]
FIG. 13 shows another embodiment of the present invention. In the pattern of FIG. 13, the thick portion 8 is disposed on the side CD connecting the C corner and the D corner of the pixel electrode 6, and the short branch portions 8a are provided at both ends to form the corner portion 8c. is there. According to this embodiment, there is an advantage that foreign matter is completely prevented from being brought into rubbing in the direction of arrow L.
[0053]
Up to now, in the pixel arrangement of FIG. 7, an example in which the thick part 8 is arranged in the corners A, B and C where no element electrode is arranged has been shown, but FIG. 14 shows another embodiment of the present invention. The example which provided the thick part in the corner D with an element electrode is shown. In this embodiment, the overlapping portion of the pixel electrode and the chromium film shows an example of a tantalum / tantalum oxide / chromium / ITO structure. FIG. 14 is a sectional view taken along line BB ′ of FIG. In this example, when the pattern of the tantalum alloy film to be the first metal film 12 is formed, the tantalum alloy film pattern is also left in a place corresponding to the position of the second metal film 16b. An insulating film 14 and a second metal film 16 are formed simultaneously with the formation of the TFD element electrode thereon, and finally an ITO film 15 is formed. In this embodiment, a thick portion 8 is formed at the D corner of the pixel electrode 6. In this embodiment, the rubbing direction can be handled in the case of rubbing in the direction opposite to M shown in FIG.
[0054]
In the above embodiment, the TFD element that is a two-terminal nonlinear element has been described as the switching element. However, a TFT element that is a three-terminal nonlinear element may be used. In the case of a TFT element, the thick portion 8 can be formed using a thin film laminated structure composed of, for example, a gate electrode metal film, a gate insulating oxide film, a semiconductor film, and an ITO film.
[0055]
In the above description of the embodiment, the structure of the TFD element has been described by taking the back-to-back structure, but of course, a cross structure may be used.
[0056]
Further, although an example of a TFD driving element has been described as a two-terminal nonlinear element, the present invention is a bidirectional diode such as a zinc oxide (Zn0) varistor, a MIS (Metal Semi-Insurator) driving element, and an RD (Ring Diode). The present invention can also be applied to an active matrix drive type liquid crystal display panel having a two-terminal nonlinear element having characteristics.
[0057]
Furthermore, using the thick portion of the present invention, the two substrates of the element substrate and the counter substrate can also be used as an alignment marker when the predetermined pixel electrode regions are opposed to each other and bonded accurately. it can. In this case, since the opaque thick first metal film and second metal film are included in the thick portion, it is convenient for visual judgment.
[0058]
Next, electronic equipment using the liquid crystal device of the present invention will be described.
[0059]
An example of an electronic device using the liquid crystal device of the present invention is shown in FIG.
[0060]
FIG. 15A is a perspective view showing an example of a mobile phone. Reference numeral 1000 denotes a mobile phone body, of which 1001 is the liquid crystal device of the present invention.
[0061]
FIG. 15B is a perspective view showing an example of a wristwatch type electronic apparatus. Reference numeral 1100 denotes a watch body, and 1101 denotes a liquid crystal device of the present invention.
[0062]
FIG. 15C is a perspective view showing an example of a portable information processing apparatus such as a word processor or a personal computer. In the figure, reference numeral 1200 denotes an information processing apparatus, 12002 is an input unit such as a keyboard, 1204 is an information processing apparatus body, and 1206 is a liquid crystal device of the present invention.
When the liquid crystal device of the present invention is used for these electronic devices, not only does the display surface have no point defects, but the display device is easy to see, and the production yield is greatly improved, which greatly contributes to cost reduction.
[0063]
As another example of the electronic apparatus, an example of a projector (projection display device) using the liquid crystal device of the present invention as a light modulation device is shown in FIG.
[0064]
The projector of this example includes a polarized light illuminating device 100 roughly constituted by a light source unit 110, an integrator lens 120, and a change conversion element 130 arranged along the system optical axis L, and an S-polarized light beam emitted from the polarized light illuminating device 100. The polarized beam splitter 200 that is reflected by the S-polarized light beam reflecting surface 201, the dichroic mirror 412 that separates the blue light (B) component out of the light reflected from the S-polarized light reflecting surface 201 of the polarized beam splitter 200, and the separated blue color Reflected liquid crystal light modulator 300B that modulates blue light, dichroic mirror 413 that reflects and separates red light (R) component of the light flux after blue light is separated Reflective liquid crystal light modulator 300R that modulates red light (R) and the remaining green light that passes through dichroic mirror 413 (G) is modulated by the reflection type liquid crystal light modulation device 300G, and the light modulated by the three reflection type liquid crystal light modulation devices 300B, 300R, and 300G is synthesized by the dichroic mirrors 412 and 413 and the polarization beam splitter 200. The projection optical system 500 includes a projection lens that projects the combined light onto the screen 600. The liquid crystal devices of the present invention are used for the three reflective liquid crystal light modulation devices 300R, 300G, and 300B, respectively. By using the liquid crystal device of the present invention, it is possible to suppress the occurrence of product defects.
[0065]
【The invention's effect】
According to the present invention, in the rubbing process step, since there is a thick part in front of the switching element in the rubbing direction, the impact by the brush tip for rubbing can be reduced, and foreign matter can be prevented from entering. Are not scratched, point defects due to device defects are eliminated, a high-quality screen is obtained, and the production yield of a liquid crystal panel is improved.
[0066]
In addition, since the possibility of scratching is reduced, the pressing pressure of the brush during the rubbing process can be increased, so that the rubbing effect is enhanced and the high-quality screen with stronger contrast can be obtained. .
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a rubbing direction.
FIG. 2 is a partial plan view showing an embodiment of a liquid crystal device according to the present invention.
FIG. 3 is a plan view showing an embodiment of a TFD driving element used in the liquid crystal device according to the present invention.
4 is a diagram showing a cross-sectional structure along the line AA ′ in FIG. 3;
FIG. 5 is a plan view showing another embodiment of a TFD drive element used in the liquid crystal device according to the present invention.
6 is a view showing a cross-sectional structure along the line BB ′ in FIG. 5;
FIG. 7 is a plan view showing one embodiment of an element substrate of a liquid crystal panel used in a liquid crystal device according to the present invention.
8 is a diagram showing a cross-sectional structure along the line XX ′ in FIG. 7;
FIG. 9 is a diagram showing a state where an element substrate and a counter substrate are bonded together.
FIG. 10 is a diagram showing another embodiment of the present invention.
FIG. 11 is a diagram showing still another embodiment of the present invention.
FIG. 12 is a diagram showing still another embodiment of the present invention.
FIG. 13 is a diagram showing still another embodiment of the present invention.
FIG. 14 is a diagram showing another embodiment of the present invention.
FIG. 15 illustrates an example of an electronic device using the liquid crystal device of the invention.
FIG. 16 is a diagram illustrating another example of an electronic device using the liquid crystal device of the invention.
[Explanation of symbols]
1 ... element substrate,
2 ... counter substrate,
3 ... Liquid crystal injection port,
4 ... seal part,
5 ... sealing part,
6: Pixel electrode,
7: Wiring part,
8 ... Thick part,
9 ... Alignment film,
10 TFD drive element,
11 ... the overlapping part of the second metal film and the ITO film,
12 ... 1st metal film,
14 ... Insulating film,
15 ... ITO film,
16 ... second metal film,
20 ... TFD drive element,
22 ... 1st metal film,
24 ... Insulating film,
26 ... second metal film,
30 ... Liquid crystal substance,
31 ... Insulating film,
50 ... Drive IC,
51 ... Input terminal,
L, M ... rubbing direction,
1000 ... mobile phone,
1100 ... watch,
1200 ... notebook computer,
100: Polarized illumination device,
200: Polarizing beam splitter,
300: Liquid crystal light modulator,
412 ... Dichroic mirror,
500 ... Condensing lens,
600 ... Screen

Claims (8)

An element substrate having a pixel electrode on a substrate, a switching element provided at a corner of the pixel electrode, a wiring connected to the switching element, and an alignment film rubbed in a predetermined direction, and the element In a liquid crystal device having a counter substrate disposed to face the substrate, on the upstream side in the rubbing direction passing through the switching element, at an adjacent corner of the pixel electrode adjacent to the wiring of the switching element, A thick part having the same thin film laminated structure as the switching element is formed ,
The liquid crystal device according to claim 1, wherein the thick portion comprises a thin film laminated structure of a gate electrode metal film, a gate insulating oxide film, a semiconductor film, and ITO .   2. The liquid crystal device according to claim 1, wherein a thick portion having the same thin-film laminated structure as that of the switching element is further formed in a diagonal corner portion of the pixel electrode that forms a diagonal across the switching element and the wiring. A liquid crystal device characterized by being made. An element substrate having a pixel electrode on a substrate, a switching element provided at a corner of the pixel electrode, a wiring connected to the switching element, and an alignment film that is rubbed in a predetermined direction, and the element In a liquid crystal device having a counter substrate disposed to face the substrate,
A thick portion having the same thin film laminated structure as that of the switching element at the diagonal corner of the pixel electrode that forms a diagonal across the switching element and the wiring, upstream of the rubbing direction passing through the switching element Is formed ,
The liquid crystal device according to claim 1, wherein the thick portion comprises a thin film laminated structure of a gate electrode metal film, a gate insulating oxide film, a semiconductor film, and ITO .   4. The liquid crystal device according to claim 1, wherein the thick portion has branch portions extending in directions substantially perpendicular to each other along a direction of a side adjacent to the corner portion. 5. apparatus. Switching on the pixel electrode on the substrate and the corner of the pixel electrode In a liquid crystal device including an element, an element substrate having a wiring connected to the switching element, an alignment film that is rubbed in a predetermined direction, and a counter substrate disposed to face the element substrate. A thick portion having the same thin film laminated structure as that of the switching element is formed on the upstream side of the rubbing direction passing through the switching element and at an adjacent corner of the pixel electrode adjacent to the switching element along the wiring. And
The liquid crystal device, wherein the thick portion has a thin film laminated structure of metal tantalum, tantalum oxide, metal chromium and indium tin oxide. 6. The liquid crystal device according to claim 5, wherein a thick portion having the same thin film laminated structure as that of the switching element is further formed at a diagonal corner portion of the pixel electrode that forms a diagonal across the switching element and the wiring. A liquid crystal device characterized by being made. An element substrate having a pixel electrode on a substrate, a switching element provided at a corner of the pixel electrode, a wiring connected to the switching element, and an alignment film that is rubbed in a predetermined direction, and the element In a liquid crystal device having a counter substrate disposed to face the substrate,
  A thick portion having the same thin-film laminated structure as the switching element at the diagonal corner of the pixel electrode that forms a diagonal across the switching element and the wiring, upstream of the rubbing direction passing through the switching element Is formed,
The liquid crystal device, wherein the thick portion has a thin film laminated structure of metal tantalum, tantalum oxide, metal chromium and indium tin oxide. An electronic apparatus comprising the liquid crystal device according to any one of claims 1 to 7 .

Images