JP2004177593A - Substrate for electro-optical device, method for manufacturing same, electro-optical device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent display characteristics from deteriorating due to a recess, in an electro-optical device constituted to use a substrate having a layer with the recess. <P>SOLUTION: A color filter substrate 11, i.e. the substrate for the electro-optical device has an over-coat layer 22 with the recess 28. The side of the recess 28 is a slope 47 of which a part slopes gradually, the residual part is at least any one from among which slopes sharply, which is a substantially at right angles or which slopes outwardly from the edge of the recess. Disconnection of an electrode 23a can be prevented, by having the gentle slope 47. In addition, if the side except therefor is formed at a steep slope or at right angles, the layer thickness of a liquid crystal layer 14 can be prevented from becoming unfinished between a thick part E and a thin part F. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate used for an electro-optical device such as a liquid crystal device, a method of manufacturing the substrate, the electro-optical device, and an electronic device formed using the electro-optical device.
[0002]
[Prior art]
2. Description of the Related Art In recent years, electro-optical devices such as liquid crystal devices have been widely used for electronic devices such as mobile phones and personal digital assistants. For example, an electro-optical device is used to visually display various types of information on electronic devices.
[0003]
Looking at a liquid crystal device as an example of an electro-optical device, the liquid crystal device generally has a pair of substrates and a liquid crystal sealed in a gap formed between the substrates, that is, a so-called cell gap. Conventionally, as this liquid crystal device, a so-called reflection type liquid crystal device in which external light such as room light or sunlight is reflected in the liquid crystal panel and used for display, and light transmitted from the illumination device and transmitted through the liquid crystal panel is used. A so-called transmissive liquid crystal device of a type used for display, and a so-called transflective liquid crystal device capable of selectively performing both reflective display and transmissive display as desired. Is known.
[0004]
The following configuration of the transflective liquid crystal device is as follows: a reflective layer is provided inside a liquid crystal panel, and an opening is formed in a part of the reflective layer. 2. Description of the Related Art There is known a liquid crystal device having a configuration in which light is supplied to a liquid crystal layer and transmitted light is supplied to a liquid crystal layer through an opening. In addition, instead of forming the opening, a configuration is known in which the thickness of the reflection layer is reduced to form the transmission portion.
[0005]
Regarding such a configuration for transflective reflection, external light passes through the liquid crystal layer twice in a reciprocating manner during reflective display when external light is reflected by the reflective layer and supplied to the liquid crystal layer, while during transmissive display. Light supplied to the liquid crystal layer through the transmission portion passes through the liquid crystal layer only once. For this reason, unless any measures are taken, when one of the reflective display and the transmissive display is set to be bright, the other will be dark, and both should be set to good display conditions. There was a problem that was difficult.
[0006]
In order to solve this problem, conventionally, a technique has been proposed in which a layer having a depression is formed on the surface of one substrate constituting a liquid crystal device. According to this technique, for example, by locating the depression corresponding to the transmission part, it is possible to change the layer thickness of the liquid crystal layer corresponding to the transmission part and the layer thickness of the liquid crystal layer corresponding to the reflection part. Thus, the display quality can be made uniform between the transmissive portion and the reflective portion (for example, see Patent Document 1).
[0007]
[Patent Document 1]
JP 2001-221995 (Page 5, FIG. 1)
[0008]
[Problems to be solved by the invention]
In a conventional substrate in which a layer having a depression as described above is provided on a base material, when a depression is formed by performing a patterning method such as a photolithography method, a wall that forms the depression, that is, a depression is formed. The slope, that is, the taper, was formed on the side surface. Such a taper is inevitably formed due to a manufacturing technique, or when an electrode is formed on a layer having a depression, the electrode is formed at the position of the depression. It is also possible to avoid disconnection.
[0009]
However, in terms of the thickness of the liquid crystal layer, the portion where the taper is formed is not a thin portion of the liquid crystal layer, a thick portion of the liquid crystal device, or an optically half-finished portion. Characteristics may be degraded.
[0010]
The present invention has been made in view of the above-described problems, and in an electro-optical device configured using a substrate having a layer having a depression, display characteristics deteriorate due to the depression. The purpose is to prevent.
[0011]
[Means for Solving the Problems]
(1) In order to achieve the above object, an electro-optical device substrate according to the present invention is a substrate for an electro-optical device having a layer having a depression, wherein a side surface of the depression has a slope in which a part thereof is gently inclined. Wherein the remaining portion of the side surface is at least one of a steeper slope than the slope, a substantially right angle, and a slope outside the edge of the depression. .
[0012]
According to this substrate, a part of the side surface of the depression, that is, a part of the wall forming the depression is always provided with a gentle slope, so that the electrodes and the like are formed on the layer in which the depression is formed. Even in such a case, there is almost no inconvenience that the electrode is disconnected at the depression. Furthermore, since only a part of the depression is provided with the gentle slope, the region where the layer thickness of the electro-optical material layer such as the liquid crystal layer is halfway is only a very limited region, and therefore, There is almost no inconvenience that the display quality is deteriorated.
[0013]
In the above configuration, “steeply tilting” means that the thickness of the layer of the electro-optical material changes suddenly from a thin region to a thick region so that the thickness of the layer does not become halfway optically. That is, it is inclined within the range of The boundary between “steep slope” and “slow slope” is determined based on the above function, and it is difficult to specify a specific numerical value. The above is considered steep.
[0014]
Incidentally, with respect to the side surface of the dent, in the remaining portion other than the portion that is gently inclined, if an inclined portion inclined to the outside of the dent, that is, if a reverse tapered portion is formed, if an electrode is formed on a layer having this dent, When this electrode is viewed in plan, no space is formed between the electrodes at the side surface of the depression, so that light leakage can be prevented.
[0015]
(2) The substrate having the above structure can include a coloring layer and an electrode. In this case, the layer provided with the depression may be an overcoat layer provided between the colored layer and the electrode. The overcoat layer has a main function of insulation, flattening, and the like, and it is convenient to form a depression or an inclined portion in the overcoat layer because it is relatively easy.
[0016]
(3) The substrate having the above configuration can have a reflective portion formed by the reflective layer and a transmissive portion formed by forming an opening in the reflective layer or making the reflective layer thinner. In that case, it is desirable that the depression is provided corresponding to the transmission portion, and furthermore, the gentlely inclined portion is provided over the reflection portion, the transmission portion, or both the reflection portion and the transmission portion. It is desirable.
[0017]
If a portion that is gently inclined is provided corresponding to the reflective portion, the thickness of the liquid crystal layer corresponding to the transmissive portion does not become halfway, which is convenient for a display that emphasizes transmissive display. On the other hand, if a portion that is gently inclined is provided corresponding to the transmissive portion, the thickness of the liquid crystal layer corresponding to the reflective portion does not become halfway, which is convenient for a display that emphasizes reflective display.
[0018]
(4) In the above configuration, it is preferable that the depression is provided corresponding to a display dot which is a minimum unit of display. Thereby, it is possible to switch between the reflective display and the transmissive display for each display dot.
[0019]
(5) In the configuration described above, the planar shape of the depression may be rectangular. In this case, it is desirable that the portion that is gently inclined is formed on the short side of the rectangular shape. In this way, the wall portion that is gently inclined does not become an unnecessarily large area, and the inclination angle can be increased as necessary.
[0020]
(6) In the above configuration, it is desirable that a portion where the side surface that is gently inclined is formed is 50% or less of the entire wall, and desirably 25% or less. In this case, disconnection of the electrodes and the like formed on the layer having the depressions can be reliably prevented, and inconvenience caused by providing the inclined portion, for example, because the thickness of the liquid crystal layer becomes halfway Display quality can be minimized.
[0021]
(7) Next, in the method of manufacturing a substrate for an electro-optical device according to the present invention, a step of forming a photosensitive material, which is a material of a layer having a depression, to a uniform thickness; Exposing the layer through a mask having a pattern corresponding to the shape of the depression, and developing the exposed layer of uniform thickness to reveal the depression, wherein the mask A part having a gentle slope is formed in a part of the side surface of the depression by the halftone region provided in the first and second pits.
[0022]
According to this manufacturing method, a portion having a gentle slope can be formed very simply and inexpensively at a portion of the depression.
[0023]
(8) Next, the electro-optical device according to the present invention is disposed between the electro-optical device substrate having the above-described configuration, the opposing substrate facing the electro-optical device substrate, and the substrates. And an electro-optical material layer. In this electro-optical device, the electro-optical material may be a liquid crystal. Such an electro-optical device is a liquid crystal device.
[0024]
(9) An electronic apparatus according to an aspect of the invention includes the electro-optical device having the above-described configuration, and a control unit that controls an operation of the electro-optical device. As such an electronic device, for example, a mobile phone, a personal digital assistant, and various other electronic devices can be considered.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiments of electro-optical device substrate and electro-optical device)
Hereinafter, an embodiment in which the present invention is applied to an active matrix type liquid crystal device using a two-terminal switching element will be described. This embodiment is an example of the present invention and does not limit the present invention. In the following description, reference will be made to the drawings as necessary, but in the drawings, in order to clearly show important components of a structure including a plurality of components, relative components different from actual ones will be described. The dimensions are shown.
[0026]
FIG. 1 shows an embodiment of an electro-optical device substrate and an electro-optical device according to the present invention. More specifically, an embodiment of a liquid crystal device as an electro-optical device and an embodiment of a substrate used in the liquid crystal device are shown. The liquid crystal device described here is of an active matrix type using a TFD (Thin Film Diode) which is a two-terminal switching element, and uses a color filter substrate as a substrate for an electro-optical device. This is a reflection type liquid crystal device.
[0027]
In FIG. 1, a liquid crystal device 1 includes a liquid crystal panel 2, a driving IC 3 mounted on the liquid crystal panel 2, and a lighting device 4. The illumination device 4 is provided on the back side of the liquid crystal panel 2 when viewed from the observation side (that is, the upper side in the figure), and functions as a backlight. The illumination device 4 may be provided on the observation side of the liquid crystal panel 4 and function as a front light.
[0028]
The illumination device 4 includes a light source 6 configured by a point light source such as an LED (Light Emitting Diode) or a linear light source such as a cold cathode tube, and a light guide 7 formed of a translucent resin. Have. On the back side of the light guide 7 as viewed from the observation side, a reflection layer 8 is provided as necessary. On the observation side of the light guide 7, a diffusion layer 9 is provided as necessary.
[0029]
The liquid crystal panel 2 includes a color filter substrate 11 as an electro-optical device substrate, an element substrate 12 as a counter substrate, and a square or rectangular ring-shaped sealing material 13 viewed from the direction of arrow A where the substrates are bonded. And The liquid crystal 14 is sealed in a gap surrounded by the substrate 11, the substrate 12, and the sealing material 13, that is, a so-called cell gap, to form a liquid crystal layer.
[0030]
The color filter substrate 11 has a rectangular or square first base material 16a viewed from the direction of arrow A, and a resin scattering layer 17 is formed on the inner surface of the first base material 16a, and a reflective layer is formed thereon. 18, a colored layer 19 and a light-shielding layer 21 are formed thereon, an overcoat layer 22 is formed thereon, and an electrode 23a extending linearly in a direction perpendicular to the paper is formed thereon. An alignment film 24a is formed thereon. The alignment film 24a is subjected to an alignment process, for example, a rubbing process, whereby the alignment of the liquid crystal molecules near the first base material 16a is determined. Further, a retardation plate 26a and a polarizing plate 27a are attached to the outer surface of the first base material 16a by bonding or the like.
[0031]
The first base material 16a is formed of, for example, translucent glass, translucent plastic, or the like. Fine irregularities are formed on the surface of the resin scattering layer 17 as shown in FIG. The reflection layer 18 is formed of, for example, Al (aluminum), an Al alloy, or the like. The surface of the reflective layer 18 has an uneven shape corresponding to the unevenness formed on the resin scattering layer 17 which is the underlying layer. The light reflected by the reflective layer 18 is diffused by the uneven shape.
[0032]
For example, as shown in FIG. 4, each of the coloring layers 19 is formed in a rectangular dot shape, and one coloring layer 19 has three primary colors of R (red), G (green), and B (blue). Either one is presented. The colored layers 19 of these colors are arranged in a stripe arrangement, a delta arrangement, a mosaic arrangement, or any other appropriate arrangement. FIG. 4 illustrates a stripe arrangement. Note that the coloring layer 19 can also be formed with three primary colors of C (cyan), M (magenta), and Y (yellow).
[0033]
In FIG. 1, the light-shielding layer 21 is formed of a light-shielding material such as Cr (chrome) so as to fill the gap between the plurality of colored layers 19. The light shielding layer 21 functions as a black matrix and improves the contrast of an image displayed by light transmitted through the coloring layer 19. The light-shielding layer 21 is not limited to being formed of a specific material such as Cr, but may be formed by, for example, stacking, that is, stacking, each of the R, G, and B coloring layers constituting the coloring layer 19. can do.
[0034]
The overcoat layer 22 is formed of, for example, a photosensitive resin such as an acrylic resin or a polyimide resin. In addition, a through-hole 28 reaching the surface of the colored layer 19 is formed in a proper place of the overcoat layer 22 to form a depression, as shown in FIG. The depression 28 is not limited to the through hole, and may be formed by a bottomed hole, that is, a concave portion having a depth halfway in the overcoat layer 22 without reaching the surface of the coloring layer 19.
[0035]
The electrode 23a extending linearly in the direction perpendicular to the paper of FIG. 2 is formed of, for example, a metal oxide such as ITO (Indium Tin Oxide), and a part of the center thereof falls into the depression 28. Further, the alignment film 24a formed thereon is formed of, for example, polyimide or the like, and a portion corresponding to the depression 28 also falls into the depression 28 with respect to the alignment film 24a. That is, when viewed two-dimensionally from the direction of arrow A, a plurality of depressions are formed in the electrode 23a and the alignment film 24a.
[0036]
In FIG. 1, the element substrate 12 facing the color filter substrate 11 has a second base material 16b. One side of the second base material 16b, on which the overhang portion 29 is formed, protrudes outside the first base material 16a. A plurality of TFDs 31 as switching elements are formed on the inner surface of the second base material 16b, a plurality of dot electrodes 23b are formed so as to connect to the TFDs 31, and an alignment film 24b is formed thereon. You. The alignment film 24b is subjected to an alignment process, for example, a rubbing process, whereby the alignment of the liquid crystal molecules near the second base material 16b is determined. A retardation plate 26b and a polarizing plate 27b are attached to the outer surface of the second base material 16b by bonding or the like.
[0037]
The second base material 16b is formed of, for example, translucent glass, translucent plastic, or the like. The dot electrode 23b is formed of a metal oxide such as ITO. The alignment film 24b is formed of, for example, polyimide or the like.
As shown in FIG. 5, each TFD 31 is formed by connecting a first TFD element 32a and a second TFD element 32b in series. The TFD element 31 is formed, for example, as follows. That is, first, the first layer 34a of the line wiring 33 and the first metal 36 of the TFD element 31 are formed by TaW (tantalum tungsten). Next, the second layer 34b of the line wiring 33 and the insulating film 37 of the TFD element 31 are formed by anodizing. Next, the third layer 34c of the line wiring 33 and the second metal 38 of the TFD element 31 are formed by, for example, Cr (chromium).
[0038]
The second metal 38 of the first TFD element 32a extends from the third layer 34c of the line wiring 33. Further, the dot electrode 23b is formed so as to overlap the tip of the second metal 38 of the second TFD element 32b. Considering that an electric signal flows from the line wiring 33 to the dot electrode 23b, in the first TFD element 32a, the electric signal flows in the order of the second electrode 38, the insulating film 37, and the first metal 36 according to the current direction. In the second TFD element 32b, an electric signal flows in the order of the first metal 36 → the insulating film 37 → the second metal 38.
[0039]
That is, a pair of electrically opposite TFD elements are connected in series between the first TFD element 32a and the second TFD element 32b. Such a structure is generally called a back-to-back structure, and the TFD element having this structure is compared with a case where the TFD element is configured by only one TFD element. It is known that stable characteristics can be obtained. In order to prevent the first metal 36 or the like from peeling off from the second base material 16b or to prevent impurities from diffusing from the second base material 16b to the first metal 36 or the like, the TFD 31 and the base material An underlayer (not shown) may be provided between the base wiring 16b and the line wiring 33 and the base 16b.
[0040]
In FIG. 1, a wiring 39 is formed on the overhanging portion 29 of the second base material 16b at the same time when, for example, the TFD 31 and the dot electrode 23b are formed. In addition, the wiring 41 is formed on the first base material 16a at the same time when the reflective layer 18 and the linear electrode 23a are formed, for example. Inside the sealing material 13, a spherical or cylindrical conductive material 42 is contained in a dispersed state. The wiring 41 on the first base 16 and the wiring 39 on the second base 16 b are electrically connected to each other by the conductive material 42, so that the linear electrode 23 a on the color filter substrate 11 side is connected to the element substrate 12 side. Is electrically connected to the wiring 39.
[0041]
The driving IC 3 is mounted on the substrate overhang portion 29 of the element substrate 12 by an ACF (Anisotropic Conductive Film) 43. More specifically, the driving IC 3 is fixed on the overhang portion 29 by the resin constituting the ACF 43, and the bumps or terminals of the driving IC 3 and the wiring 39 are conductively connected by conductive particles included in the ACF 43.
[0042]
An external connection terminal 44 is formed on the edge of the overhang portion 29, and the external connection terminal 44 is conductively connected to the bump of the driving IC 3 by the ACF 43. A wiring board (not shown), for example, a flexible wiring board, is connected to the external connection terminal 44 by a conductive connection method such as soldering, ACF, or heat sealing. Signals, power, and the like are supplied to the liquid crystal device 1 from an electronic device, for example, a mobile phone or a portable information terminal, via the wiring board.
[0043]
In FIG. 1, the linear electrodes 23a on the color filter substrate 11 side and the dot electrodes 23b on the element substrate 12 side overlap each other in a plan view as viewed in the direction of arrow A. The overlapping area forms a display dot D which is the minimum unit of display. As shown in FIG. 4, the display dot D has an area of substantially the same size as the dot electrode 23b. In FIG. 4, the dot electrode 23b indicated by the dashed line is drawn slightly larger than the colored layer 19 indicated by the solid line, but this is for the sake of easy understanding of the structure. They have the same shape and overlap each other.
In FIG. 4, each dot-shaped coloring layer 19 is formed corresponding to each display dot D. In FIG. 2, the reflective layer 18 has openings 46 corresponding to the individual display dots D. As shown in FIG. 4, these openings 46 are formed in a rectangular shape in plan view. In FIG. 4, the opening 46 shown by a broken line is drawn slightly larger than the recess 28 of the overcoat layer 22 shown by a solid line, but when viewed in plan, both edges are formed on one side of the recess 28. Except for the gently inclined portion 47, they almost coincide with each other.
[0044]
When color display is performed using the colored layers 19 of three colors R, G, and B as in the present embodiment, three colors corresponding to the three colored layers 19 corresponding to the three colors of R, G, and B are used. One display dot D forms one pixel. On the other hand, when a monochrome display such as black and white is performed without using a colored layer, one pixel is formed by one display dot D.
[0045]
In FIG. 2, a portion R where the reflection layer 18 is provided in each display dot D is a reflection portion, and a portion T where the opening 46 is formed is a transmission portion. External light incident from the observation side, that is, external light L0 incident from the element substrate 12 side, is reflected by the reflector R. On the other hand, the light L1 emitted from the light guide 7 of the illumination device 4 in FIG. 1 passes through the transmission portion T in FIG.
[0046]
According to the present embodiment having the above configuration, when external light such as sunlight or indoor light is strong, the external light L0 is reflected by the reflecting portion R and supplied to the liquid crystal layer 14. On the other hand, when the illumination device 4 in FIG. 1 is turned on, the planar light emitted from the light guide 7 is supplied to the liquid crystal layer 14 through the transmission part T in FIG.
[0047]
A scanning voltage is applied to one of the linear electrodes 23a and the dot electrodes 23b sandwiching the liquid crystal layer 14, and a data voltage is applied to the other. The TFD 31 attached to the display dot D to which the scanning voltage and the data voltage are applied is turned on, and the alignment state of the liquid crystal molecules in the display dot D is maintained so as to modulate the light passing through the display dot D. Depending on whether or not the modulated light passes through the polarizing plate 27b in FIG. 1, a desired image such as a character, a numeral, a graphic, or the like is displayed on the outside of the element substrate 12. A case where display is performed using the external light L0 is a reflective display, and a case where display is performed using the transmitted light L1 is a transmissive display.
[0048]
When a reflective display is performed, the reflected light L0 passes through the liquid crystal layer 14 twice. Further, when the transmissive display is performed, the transmitted light L1 passes through the liquid crystal layer 14 only once. For this reason, if the layer thickness of the liquid crystal layer 14 is uniform over the reflective portion R and the transmissive portion T, between the reflective display using the reflected light L0 and the transmissive display using the transmitted light L1, There is a possibility that a difference occurs in a distance passing through the liquid crystal layer 14, and a problem that display quality differs between the reflective display and the transmissive display may occur.
[0049]
In this regard, in the present embodiment, by providing the depression 28 in the overcoat layer 22, the layer thickness E of the liquid crystal layer 14 in the transmission part T is increased and the layer thickness F in the reflection part R is reduced. In addition, uniform display quality can be obtained between the reflective display and the transmissive display.
[0050]
The cross-sectional structure shown in FIG. 2 is a cross-sectional structure along line XX in FIG. 2, the side surface of the depression 28 formed in the overcoat layer 22 is formed so as to be substantially perpendicular to the surface of the overcoat layer 22 or to be steeply inclined. On the other hand, the cross-sectional structure along the line YY in FIG. 4 is as shown in FIG. As shown in FIG. 3, the right side surface of the depression 28 is formed so as to be substantially perpendicular to the surface of the overcoat layer 22 or to be steeply inclined. However, the left side surface 47 is slightly inclined with respect to the surface of the overcoat layer 22.
[0051]
Here, the steep inclination means such an inclination that the difference between the thick portion E and the thin portion F of the liquid crystal layer 14 does not become a halfway liquid crystal layer thickness in display. On the other hand, the gentle inclination means a gentle inclination such that a layer formed on the overcoat layer 22, for example, the electrode 23a or the alignment film 24a is not cut. As is clear from FIG. 4, the gentle inclined portion 47 of the side surface of the depression 28 is formed on one of two short sides of the four sides of the rectangular shape in plan view. That is, the gentle inclined portion 47 is provided at a ratio of 50% or less of the entire side surface, more specifically, at a ratio of 25% or less of the entire wall.
[0052]
If all the side surfaces of the depression 28 are steeply inclined or substantially perpendicular, the thickness of the liquid crystal layer 14 between the thick portion E and the thin portion F between the transmission portion T and the reflection portion R is suddenly increased. It can be varied, and therefore it is considered that good display quality can be obtained. However, in this case, the electrode 23a and the alignment film 24a are cut off at the depression 28, and the display quality may be deteriorated for another reason.
[0053]
On the other hand, in the present embodiment, since the gentle inclined portion 47 is provided in a part of the depression 28, it is possible to prevent the electrode 23a and the alignment film 24a from being cut in that part, thereby preventing the display quality from deteriorating. it can. Further, if the depression 28 is provided with a gentle inclined portion 47, a halfway portion of the liquid crystal layer 14 having a halfway thickness between the thick portion E and the thin portion F of the liquid crystal layer 14 occurs in a wide area, and the display quality is deteriorated. It is possible to become. However, in the present embodiment, the area in which the gentle inclined portion 47 is provided is limited to one side on the short side of the rectangular shape, that is, an area of 50% or less, preferably 25% or less of the whole. The drop is practically negligible.
[0054]
(Modification)
(1) In the above embodiment, as shown in FIGS. 2 and 3, the side surface of the depression 28 formed in the overcoat layer 22 other than the gentle inclined portion 47 is substantially a right angle or a steep inclined portion. When forming a steep slope, the slope is the slope toward the inside of the depression 28. However, instead of this, as shown in FIGS. 6 and 7, an inclined portion 57 inclined toward the outside of the depression 28, that is, a so-called reverse tapered inclined portion can be formed in the overcoat layer 22.
[0055]
If the depression 28 is formed by such an inclined portion 57 having a reverse taper, when the electrode 23a is viewed from the observation side, that is, from the arrow A side, the electrode 23a on the overcoat layer 22 and the electrode 23a on the bottom of the depression 28 are separated. Thus, no gap is generated when viewed in a plan view, so that it is possible to prevent the display quality from deteriorating due to the occurrence of light leakage or the like.
[0056]
(2) In the above embodiment, the depression 28 for changing the layer thickness of the liquid crystal layer 14 between the reflection portion R and the transmission portion T is formed in the overcoat layer 22. It can be formed in any layer.
[0057]
(3) In the above embodiment, the present invention is applied to a liquid crystal device using a TFD, but the present invention can be applied to an active matrix type liquid crystal device using a two-terminal switching element other than the TFD. The present invention is also applicable to an active matrix type liquid crystal device using a three-terminal switching element such as a TFT (Thin Film Transistor). Further, the present invention can be applied to a simple matrix type liquid crystal device which does not use a switching element. Further, the present invention can be applied to an electro-optical device other than the liquid crystal device.
[0058]
(4) In the above embodiment, the substrate for the electro-optical device according to the present invention, that is, the substrate on which the depression 28 is formed is the color filter substrate 11, but when performing monochrome display other than color display, the depression 28 is used. It is not necessary to form the colored layer 19 on the substrate on which is formed. Further, even when the colored layer 19 is formed, the depression 28 may be provided on the substrate on which the colored layer 19 is not formed, in the embodiment of FIG.
[0059]
(5) In the above embodiment, as shown in FIG. 3, the gentle inclined portion 47 of the depression 28 is formed across the boundary P between the reflection portion R and the transmission portion T. That is, the gentle slope 47 is provided over both the reflection part R and the transmission part T. However, instead of this, the gentle inclined portion 47 can be provided corresponding only to the reflecting portion R, or the gentle inclined portion 47 can be provided corresponding only to the transmitting portion T.
[0060]
From the viewpoint of the thickness of the liquid crystal layer 14, the gentle slope 47 is a halfway part that is neither the thick part E nor the thin part F. Therefore, it is considered that the portion having the gentle inclined portion 47 is a portion that may deteriorate the display quality. Therefore, when importance is placed on transmissive display, it is desirable that the gentle inclined portion 47 be provided only in correspondence with the reflecting portion R. On the other hand, when importance is placed on the reflection type display, it is desirable that the gentle inclined portion 47 is provided only in correspondence with the transmission portion T.
[0061]
(Method of manufacturing substrate for electro-optical device)
Hereinafter, a method for manufacturing an electro-optical device substrate according to the present invention will be described with reference to an example of manufacturing the electro-optical device shown in FIG. FIG. 8 shows an example of a method of manufacturing an electro-optical device including a method of manufacturing a substrate for an electro-optical device as a process chart.
[0062]
In the manufacturing method of FIG. 8, in the process P1, the color filter substrate 11 of FIG. 1 is manufactured. In step P2, the element substrate 12 of FIG. 1 is formed. In these steps, the color filter substrate 11 and the element substrate 12 are not formed one by one, but a plurality of color filters are provided on a large-area base material, that is, a so-called mother board, on which a plurality of the substrates can be formed. The substrate 11 and the plurality of element substrates 12 are formed simultaneously.
[0063]
When the plurality of color filter substrates 11 and the plurality of element substrates 12 are respectively formed on the motherboard, in a process P3, the motherboards are aligned, that is, positioned and bonded to each other. The motherboards are adhered by the sealing material 13 (see FIG. 1) formed on the crab. Thus, a large panel structure including a plurality of liquid crystal panels is formed.
[0064]
Next, in step P4, a first cutting operation, that is, a breaking operation, is performed on the panel structure to form a so-called strip-shaped panel structure in which a plurality of liquid crystal panels are built in one row. In this panel structure, with respect to a plurality of liquid crystal panels arranged in a line, openings formed at appropriate places of the sealing material (see FIG. 1), that is, liquid crystal injection ports are exposed to the outside.
[0065]
Next, in step P5, liquid crystal is injected into the inside of the liquid crystal panel from the liquid crystal injection port, and after the injection is completed, the liquid crystal injection port is sealed with a resin. Thus, a strip-shaped panel structure having a plurality of liquid crystal layers 14 as shown in FIG. 1 is formed.
Next, in step P6, a second cutting operation, that is, a breaking operation, is performed on the strip-shaped panel structure to cut out the liquid crystal panels 2 shown in FIG. 1 one by one. Next, the retardation plates 26a and 26b and the polarizing plates 27a and 27b of FIG. Next, in step P8, the driving IC 3 of FIG. 1 is mounted on the surface of the overhang portion 29 of the element substrate 12, and in step P9, a wiring board (not shown) is attached to the external connection terminals 44 on the overhang portion 29. Conductive connection is made, and in step P10, the lighting device 4 of FIG. 1 is mounted, whereby the liquid crystal device 1 of FIG. 1 is completed.
In the manufacturing process of the color filter substrate in the process P1, as shown in FIG. 9, in a process P11, the resin scattering layer 17 is formed on the first base material 16a constituting the color filter substrate 11. Specifically, a resin material is formed into a uniform thickness by, for example, spin coating, a resist is further applied, and the above-mentioned resin is passed through a mask having a pattern matching the uneven shape of the surface of the resin scattering layer 17 as shown in FIG. The resist is exposed, and the resist is developed.
[0066]
Further, the resin material is etched using the developed resist as a mask to form a concavo-convex shape, that is, a peak or a valley, in consideration of the resin material, and the surface of the resin material is further heated to an appropriate temperature to form the concavo-convex shape. Smooth the surface. Furthermore, by applying a thin resin material of the same material, the uneven shape is further smoothed so that a desired light scattering function can be achieved.
[0067]
In other words, the resin scattering layer 17 has a double structure including a lower layer whose surface is formed in a rough uneven shape by photoetching, and an upper layer laminated on the lower layer.
[0068]
Next, in step P12 of FIG. 9, the reflective layer 18 of FIG. 2 is formed by using a light-reflective metal such as Al or an Al alloy as a material by an appropriate film forming method. More specifically, first, a reflective material is formed with a uniform thickness, and an opening 46 is formed for each display dot D by photoetching.
[0069]
Next, in step P13 in FIG. 9, a light-shielding layer 21 is formed of a light-shielding material such as Cr in a region between the display dots D in FIG. Next, in a process P14 of FIG. 9, the colored layer 19 of FIG. 2 is formed in a region between the light shielding layers 21 for each of R, G, and B in a predetermined pattern, for example, a stripe arrangement. These colored layers 19 are formed, for example, by dispersing a one-color pigment in a photopolymer or photoresist to form a colored material, applying the colored material by spin coating or the like, further exposing it in the above-mentioned predetermined pattern, and further developing it. Thereby, a one-colored layer 19 is formed. By repeating this process for each of the colors R, G, and B, a color filter is formed in which the colors R, G, and B are arranged in a predetermined array.
[0070]
Next, in step P15 of FIG. 9, the overcoat layer 22 of FIG. 2 is formed. Specifically, as shown in FIG. 11B, a photosensitive overcoat material 22 ′ is formed with a uniform thickness, and the overcoat material 22 ′ is formed through a mask 49 having a pattern corresponding to the plurality of depressions 28. The material 22 'is exposed and further developed to form a depression 28 as shown in FIG. In this embodiment, a negative material is used as the overcoat material 22 ′. Therefore, a light-shielding portion 51 is formed in a mask portion corresponding to the depression 28.
[0071]
In the present embodiment, as shown in FIG. 3, since a gentle slope 47 is formed in a part of the depression 28 of the overcoat layer 22, a portion of the mask 49 corresponding to the gentle slope 47 in FIG. Is formed not by a complete light-shielding part but by a halftone part 52. With respect to the mask 49, the exposure portion 53 allows 100% of the exposure light to pass therethrough, the light shielding portion 51 blocks the exposure light, and the halftone portion 52 exposes the light at an appropriate ratio of 0 to 100%, for example, 50%. Light passes through. By irradiating the exposure light whose light amount has been reduced in this manner for an appropriate period of time, a gentle inclined portion 47 can be formed.
[0072]
Next, in step P16 in FIG. 9, the electrodes 23a are linearly formed one by one on the overcoat layer 22 in FIG. 2 by, for example, photolithography and photo-etching using ITO as a material. It is formed in a stripe shape when viewed from the direction.
[0073]
Next, in a process P17 in FIG. 9, for example, polyimide is applied to a uniform thickness on the electrode 23a in FIG. 2 to form an alignment film 24a, and a rubbing process is performed. Thus, the color filter substrate 11 of FIG. 1 is formed.
[0074]
The manufacturing process of the counter substrate, that is, the element substrate, performed in the process P2 of FIG. 8 is performed, for example, as illustrated in FIG. First, in step P21, the TFD 31 and the line wiring 33 are formed as shown in FIG. Next, in a process P22 of FIG. 10, the dot electrode 23b of FIG. 3 is formed into a predetermined dot shape by a photolithography method and a photo etching method using ITO as a material. Next, in step P23 of FIG. 10, polyimide is applied on the dot electrode 23b of FIG. 3 with a uniform thickness, and a rubbing process is further performed. Thus, the element substrate 12 of FIG. 1 is formed.
[0075]
(Embodiment of electronic device)
Next, an embodiment of an electronic device according to the present invention will be described with reference to the drawings. FIG. 12 illustrates a block diagram of an embodiment of an electronic device. The electronic device shown here includes the liquid crystal device 1 and a control unit 60 that controls the liquid crystal device 1. The liquid crystal device 1 has a liquid crystal panel 61 and a drive circuit 62 composed of a semiconductor IC or the like. The control means 60 includes a display information output source 63, a display information processing circuit 64, a power supply circuit 66, and a timing generator 67.
[0076]
The display information output source 63 includes a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage unit such as a magnetic recording disk or an optical recording disk, and a tuning circuit for synchronizing and outputting a digital image signal. Having. Based on various clock signals generated by the timing generator 67, the display information is supplied to the display information processing circuit 64 in the form of an image signal in a predetermined format or the like.
[0077]
The display information processing circuit 64 includes various known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit. Is supplied to the drive circuit 62 together with the clock signal CLK. The driving circuit 62 includes a scanning line driving circuit, a data line driving circuit, and an inspection circuit. The power supply circuit 66 supplies a predetermined voltage to each of the above components.
[0078]
FIG. 13 shows an embodiment in which the present invention is applied to a mobile phone as an example of an electronic device. The mobile phone 70 shown here has a main body 71 and a display body 72 provided to be openable and closable on the main body. The display device 73 is arranged inside the display unit 72, and various displays related to telephone communication can be visually recognized on the display screen 74 on the display unit 72. Operation buttons 76 are arranged on the front surface of the main body 71. Further, an antenna 77 is mounted to be able to protrude and retract from one end of the display body 72. A speaker is arranged inside the receiving section 78, and a microphone is built inside the transmitting section 79.
[0079]
FIG. 14 illustrates an embodiment in which the present invention is applied to a portable information device that is an example of an electronic device. The portable information device 90 shown here is an information device provided with a touch panel, and has a liquid crystal device 91 mounted thereon. The information device 90 has a display area V formed by the display surface of the liquid crystal device 91, and a first input area W1 located below the display area V. An input sheet 92 is arranged in the first input area W1.
[0080]
The liquid crystal device 91 has a structure in which a rectangular or square liquid crystal panel and a rectangular or square touch panel are also planarly overlapped. The touch panel functions as an input panel. The touch panel is larger than the liquid crystal panel and has a shape protruding from one end of the liquid crystal panel.
[0081]
A touch panel is arranged in the display area V and the first input area W1, and an area corresponding to the display area V also functions as a second input area W2 in which an input operation can be performed similarly to the first input area W1. The touch panel has a second surface located on the liquid crystal panel side and a first surface facing the second surface, and an input sheet 92 is affixed to a position corresponding to the first input area W1 on the first surface. .
[0082]
A frame for identifying the icon 93 and the handwritten character recognition area W3 is printed on the input sheet 92. In the first input area W1, a load is applied to the first surface of the touch panel through an input sheet 92 by an input means such as a finger or a pen to select an icon 93 or input a character in the character recognition area W3. Data entry can be performed.
[0083]
On the other hand, in the second input area W2, in addition to being able to observe the image of the liquid crystal panel, the input mode screen is displayed on the liquid crystal panel, for example, and a load is applied to the first surface of the touch panel with a finger or a pen. An appropriate position in the input mode screen can be specified, and thereby data input and the like can be performed.
[0084]
(Other embodiments)
As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and can be variously modified within the scope of the invention described in the claims.
[0085]
For example, as the electronic device according to the present invention, a liquid crystal television, a digital still camera, a wristwatch, and other various electronic devices can be considered in addition to the above-described mobile phone and portable information device.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an embodiment of an electro-optical device according to the present invention and an embodiment of a substrate for an electro-optical device.
FIG. 2 is an enlarged sectional view showing a main part of FIG.
FIG. 3 is a cross section of the structure shown in FIG. 2;
FIG. 4 is a plan view showing a planar structure of a main part of the structure shown in FIG. 1;
FIG. 5 is a perspective view showing an example of a switching element used in the device of FIG.
FIG. 6 is a cross-sectional view showing a main part of another embodiment of the substrate for an electro-optical device according to the present invention.
FIG. 7 is a sectional view of the structure shown in FIG. 6;
8 is a process chart showing an example of a method for manufacturing the electro-optical device of FIG.
FIG. 9 is a process chart showing one embodiment of a method for manufacturing an electro-optical device substrate according to the present invention.
FIG. 10 is a process chart showing a main step in the manufacturing method of FIG. 8;
FIG. 11 is a view showing main steps of the manufacturing method shown in FIG. 9;
FIG. 12 is a block diagram illustrating an embodiment of an electronic device according to the invention.
FIG. 13 is a perspective view illustrating another embodiment of the electronic apparatus according to the invention.
FIG. 14 is a perspective view showing still another embodiment of the electronic apparatus according to the invention.
[Explanation of symbols]
1: liquid crystal device (electro-optical device), 2: liquid crystal panel, 3: driving IC, 4: illumination device, 11: color filter substrate (electro-optical device substrate), 12: element substrate (counter substrate), 13: Sealing material, 14: liquid crystal layer, 16a, 16b: base material, 17: resin scattering layer, 18: reflection layer, 19: coloring layer, 21: light shielding layer, 22: overcoat layer (layer with depression), 23a , 23b: electrode, 24a, 24b: alignment film, 28: depression, 31: TFD, 46: opening of reflective layer, 47: gentle slope, 49: mask, 51: light shielding part, 52: halftone part, 53: Exposure part, 57: reverse taper inclined part, 70: portable telephone (electronic equipment), 90: portable information equipment (electronic equipment), D: display dot, E: thick part of liquid crystal layer, F: thin part of liquid crystal device, L0: external light, L1: illumination light, R: reflection section T: transmission portion, V: display area

Claims (10)

In an electro-optical device substrate having a layer with a depression,
The side surface of the depression has a slope in which a part thereof is gently inclined,
The remaining portion of the side surface is at least one of a steeper slope than the slope, a substantially right angle, and a slope outside the edge of the depression. substrate. The substrate for an electro-optical device according to claim 1,
A substrate for an electro-optical device, comprising: a coloring layer; and an electrode, wherein the layer provided with the depression is an overcoat layer provided between the coloring layer and the electrode. The substrate for an electro-optical device according to claim 1 or 2,
A reflection portion formed by the reflection layer,
Having a transmission portion formed by forming an opening in the reflection layer or making the reflection layer thinner,
The depression is provided corresponding to the transmission part,
The substrate for an electro-optical device, wherein a portion of the side surface that is gently inclined is provided over the reflection portion, the transmission portion, or both the reflection portion and the transmission portion. The substrate for an electro-optical device according to at least one of claims 1 to 3,
The substrate for an electro-optical device, wherein the depression is provided corresponding to a display dot which is a minimum unit of display. The substrate for an electro-optical device according to at least one of claims 1 to 4,
The substrate for an electro-optical device, wherein the planar shape of the depression is rectangular, and the gently inclined portion is formed on a short side of the rectangle. The electro-optical device substrate according to at least one of claims 1 to 5,
The substrate for an electro-optical device, wherein a portion where the side surface that is gently inclined is formed is 50% or less of the entire side surface. Forming a photosensitive material, which is a material of a layer having a depression, to a uniform thickness;
Exposing the layer of uniform thickness through a mask having a pattern corresponding to the shape of the depression;
Developing the exposed layer of uniform thickness to reveal the depressions,
A method for manufacturing a substrate for an electro-optical device, wherein a part having a gentle slope is formed in a part of a side surface of the depression by a halftone region provided in the mask. An electro-optical device substrate according to at least one of claims 1 to 6, an opposing substrate facing the electro-optical device substrate, and an electro-optical material layer disposed between the substrates. An electro-optical device comprising: 9. The electro-optical device according to claim 8, wherein the electro-optical material is a liquid crystal. An electronic apparatus comprising: the electro-optical device according to claim 8 or 9; and control means for controlling an operation of the electro-optical device.

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