JP3823774B2 - Electro-optical device and electronic apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electro-optical device using an electro-optical material such as liquid crystal, and an electronic apparatus using the electro-optical device. More specifically, the present invention relates to a configuration of a striped electrode for driving an electro-optical material in an electro-optical device.
[0002]
[Prior art]
In recent years, electro-optical devices such as liquid crystal devices have been widely used as display units of electronic devices such as mobile phones and mobile computers. Among such electro-optical devices, for example, in an active matrix liquid crystal device using a TFD element (Thin Film Diode) which is a two-terminal nonlinear element as an active element, the TFD elements and the pixel electrodes are formed in a matrix. The element substrate and the counter substrate on which the striped electrode is formed are bonded to each other with a predetermined gap through a sealing material, and liquid crystal is injected into a region defined by the sealing material between these substrates. Is retained.
[0003]
Here, as shown in FIG. 16, the counter substrate is formed with a plurality of data lines 52 for driving the liquid crystal composed of stripe-like electrodes arranged in parallel at predetermined intervals in the region defined by the sealant 6. In addition, a wiring portion 520 extends from each of the data lines 52 toward the mounting area 80b of the liquid crystal driving IC chip.
[0004]
Further, when displaying a color image in the liquid crystal device, cross sections (cross sections AA ′, BB ′, CC ′, and DD ′ in FIG. 16) at each position of the counter substrate 7b are shown. As shown in FIG. 17, on the surface side of the transparent substrate 17b which is the base of the counter substrate 7b, there is a light shielding film 43 called a black matrix, and red (R), green (G) and blue (B) color filters 40R. , 40G, 40B, the insulating overcoat layer 45, the data line 52, and the alignment film 68 are laminated in this order. Here, the overcoat layer 45 is a film for eliminating unevenness caused by the color filters 40R, 40B, and 40B formed on the lower layer side, and is surrounded by the sealing material 6 on the surface of the counter substrate 7b. It is formed only in a predetermined region within the region (region surrounded by a two-dot chain line L2 in FIG. 16). For this reason, the data line 52 includes the formation region 45a and the non-formation region of the overcoat layer 45, as shown in FIGS. 18A and 18B by enlarging the regions surrounded by the circles F and G in FIG. 45b extends at the same width across both sides. In FIGS. 16, 18A and 18B, the region where the sealing material 6 is formed is indicated by a one-dot chain line L1, and the boundary portion between the formation region 45a and the non-formation region 45b of the overcoat layer 45 is two. The dotted line L2 indicates a region where the light shielding film 44 for screen parting is formed by a dotted line L3. 17 corresponds to a boundary portion between the formation region 45a and the non-formation region 45b of the overcoat layer 45. Although the overcoat layer 45 is shown, the light shielding films 43, 44, Also, the color filters 40R, 40G, and 40B are not formed here, and thus are not shown in the drawing.
[0005]
In the manufacturing process of the counter substrate 7b having such a configuration, when the data line 52 is formed, first, as shown in FIG. 19A, on the surface of the transparent substrate 17b, the light shielding films 43 and 44, the color filters are formed. 40R, 40G, 40B and the overcoat layer 45 are formed in this order, and then an ITO film 52 'for forming the data line 52 is formed on the entire surface of the substrate on the upper layer side of the overcoat layer 45. After the photosensitive resist 600 is applied to the entire surface of the ITO film 52 ', the photosensitive resist 600 is exposed and developed through the exposure mask 610, and as shown in FIG. 601 is formed. Next, the ITO film 52 ′ is patterned by a method such as dry etching through the resist mask 601 to form stripe-shaped data lines 52 as shown in FIG.
[0006]
[Problems to be solved by the invention]
While the liquid crystal device is strongly required to improve display quality such as high definition of images, the counter substrate 7b further narrows the pitch of the data lines 52 and increases the number of data lines 52 accordingly. Although there is a movement, if such a countermeasure is taken, there is a problem that a problem due to a short circuit of the data line 52 is likely to occur. As a result of various investigations by the inventor of the present application regarding such a defect, a short circuit between the data lines 52 occurs at the boundary between the formation region 45a and the non-formation region 45b of the overcoat layer 45 for the reason described below. The knowledge that it is easy to do was acquired.
[0007]
In other words, the overcoat layer 45 is formed as a thick film of, for example, 2000 nm to 3000 nm because it aims to eliminate the unevenness caused by the color filters 40R, 40G, and 40B. Therefore, a large step 450 is formed at the boundary between the formation region 45a and the non-formation region 45b of the overcoat layer 45, and the data line 52 passes through the step 450 as shown in FIG. For this reason, when the exposure process shown in FIG. 19A is performed, the resist 600 in the portion that should be originally exposed is not exposed due to the influence of the shadow caused by the step 450, and the portion corresponding to the step 450 is not exposed in FIG. As indicated by a dotted line L4 in FIG. 5B, an extra resist mask 601 ′ remains at a position where the ITO film 600 is to be removed. As a result, when the ITO film 52 ′ is patterned, an extra ITO film 52 ″ remains between the data lines 52 as shown in FIGS. 18A and 19C, and this extra ITO The data line 52 is short-circuited by the film 52 ″.
[0008]
Even if there is no abnormality in the exposure of the resist 600, the data line 52 is affected by the shadow caused by the step 450 when the ITO film 52 'is patterned by dry etching in the patterning step shown in FIG. In this case, an extra ITO film 52 "remains, and the extra ITO film 52" may cause a short circuit between the data lines 52.
[0009]
Moreover, when the ITO film 52 'is formed by sputtering, if the color filters 40R, 40G, and 40B made of an organic material are already formed on the lower layer side, the heat resistance of the organic material that constitutes the color filters 40R, 40G, and 40B. As a result, the ITO film 52 'cannot be sputtered under a very high temperature condition, and the ITO film 52' sputtered under such a low temperature condition cannot be patterned with high accuracy. There is also an effect that 52 ″ tends to remain.
[0010]
In view of the above problems, an object of the present invention is to provide an electro-optical device capable of reliably avoiding a short circuit of a stripe electrode on the step even if the stripe electrode passes on the step. And an electronic apparatus using the electro-optical device.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, an insulating film is formed in a predetermined region on the first substrate holding the electro-optic material, and the insulating film forming region and the non-layer are formed on the upper layer side of the insulating film. In the electro-optical device in which a plurality of stripe electrodes extend in parallel across both formation regions, a portion corresponding to a boundary between the formation region and the non-formation region of the insulating film is provided on a lower layer side of the stripe electrode. A step is formed, and the plurality of striped electrodes are characterized in that an electrode width is narrower in a portion passing over the step than in a portion passing over the formation region of the insulating film.
[0012]
In the electro-optical device, even when a large step is formed at the boundary between the formation region of the insulating film formed as an overcoat layer and the non-formation region, and the stripe electrode passes over the step, the present invention The stripe-shaped electrode has a narrower electrode width than a portion passing over the step and a portion passing through the insulating film formation region. For this reason, even when an exposure abnormality occurs due to a shadow due to a step during exposure for forming a resist mask for patterning the stripe-shaped electrode, and an extra conductive film remains between the stripe-shaped electrodes, the step There is no short circuit between the striped electrodes. In addition, when dry etching for patterning the stripe electrode is performed, even if an etching abnormality occurs due to a shadow caused by the step, and an extra conductive film remains between the stripe electrodes, the stripe is formed on the step. The electrode-like electrodes are not short-circuited.
[0013]
In the present invention, a portion of the plurality of stripe-shaped electrodes passing over the step is compared with both a portion passing over the insulating film forming region and a portion passing over the non-forming region of the insulating film. It is preferable that the width is a narrowed portion. If the width of the striped electrode is narrowed, the electrical resistance of this part increases, but if the configuration is constricted only on the step where a short circuit is likely to occur, such an increase in electrical resistance should be minimized. Can do.
[0014]
In the present invention, among the plurality of striped electrodes, a portion passing over the step and a portion passing through the non-formation region of the insulating film are narrower than a portion passing through the formation region of the insulating film. The structure which has become may be sufficient. Of the striped electrode, a portion passing over the non-insulating region of the insulating film is drawn in a predetermined pattern as a wiring portion for supplying a signal from the driving IC or the outside. In this case, since a large number of wirings can be routed in a narrow region, it is possible to cope with an increase in the number of stripe electrodes.
[0015]
In the present invention, the insulating film is an overcoat film for flattening irregularities formed by a color filter formed on a lower layer side of the insulating film. When a conductive film for forming a striped electrode is formed by sputtering, if a color filter made of an organic material has already been formed on the lower layer side, the conductive film is sputtered at a very high temperature in view of the heat resistance of the color filter. A conductive film that cannot be formed and is sputtered under such a low temperature condition cannot be patterned with high accuracy, so that an excessive conductive film tends to remain on the step. Nevertheless, in the present invention, since the width of the portion of the plurality of striped electrodes passing over the step is narrow, even if an extra conductive film remains between the striped electrodes, the striped electrodes are arranged on the step. Will not short circuit.
[0016]
In the present invention, the striped electrode is formed by patterning a sputtered film using a photolithography technique. In this case, the striped electrode is composed of a conductive metal oxide film such as an ITO film.
[0017]
In the present invention, a portion of the striped electrode having a narrower electrode width than a portion passing over the insulating film formation region has a multilayer structure of the metal oxide film and the metal film. It is preferable. With this configuration, the electrical resistance of the portion where the electrode width is narrow can be reduced, so that no signal delay occurs when a signal is supplied to the stripe electrode.
[0018]
The electro-optical device to which the present invention is applied is, for example, surrounded by the sealing material between the first substrate and the second substrate bonded to the first substrate via the sealing material. A liquid crystal device in which a liquid crystal as the electro-optical material is held in a region.
[0019]
An electro-optical device to which the present invention is applied is used as a display unit of an electronic apparatus such as a mobile phone or a mobile computer.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. In the following description of embodiments, an active matrix liquid crystal device using a TFD element as an active element among various electro-optical devices will be described as an example.
[0021]
[Configuration of LCD panel]
FIG. 1 is a block diagram schematically showing the electrical configuration of the liquid crystal device. FIGS. 2A and 2B are plan views of one pixel in the element substrate among the counter substrate (first substrate) and the element substrate (second substrate) that sandwich the liquid crystal layer in the liquid crystal panel, FIG. 3 is a cross-sectional view taken along the line II ′ of FIG. Note that since the counter substrate used in the liquid crystal device of this embodiment has a common basic configuration, portions having common functions are denoted by the same reference numerals.
[0022]
As shown in FIG. 1, in the liquid crystal panel 2 used in the liquid crystal device, scanning lines 51 as a plurality of wirings are formed in the row direction (X direction), and a plurality of data lines 52 are formed in the column direction (Y direction). Has been. A pixel 53 is formed at a position corresponding to each intersection of the scanning line 51 and the data line 52. In the pixel 53, a liquid crystal layer 54 and a TFD element 56 are connected in series. Each scanning line 51 is driven by a scanning line driving circuit 57, and each data line 52 is driven by a data line driving circuit 58. In the present embodiment, the scanning line driving circuit 57 and the data line driving circuit 58 are respectively configured as a liquid crystal driving IC 8a and a liquid crystal driving IC 8b described later with reference to FIG.
[0023]
2A and 2B, the TFD element 56 includes two TFD elements composed of a first TFD element 56a and a second TFD element 56b formed on the base layer 61 formed on the surface of the element substrate 7a. Depending on the elements, a so-called back-to-back structure is formed. Therefore, in the TFD element 56, the current-voltage nonlinear characteristic is symmetric in both positive and negative directions. The underlayer 61 is made of, for example, tantalum oxide (Ta ₂ O _Five ). The first TFD element 56a and the second TFD element 56b include a first metal layer 62, an insulating layer 63 formed on the surface of the first metal layer 62, and a second metal layer formed on the surface of the insulating layer 63 so as to be separated from each other. The metal layers 64a and 64b are configured. The first metal layer 62 is formed of, for example, a Ta single film or a Ta alloy film having a thickness of about 100 to 500 nm, and the insulating layer 63 oxidizes the surface of the first metal layer 62 by, for example, an anodic oxidation method. Tantalum oxide (Ta) having a thickness of 10 to 35 nm ₂ O _Five ).
[0024]
The second metal layers 64a and 64b are formed to a thickness of about 50 to 300 nm by a metal film such as chromium (Cr). The second metal layer 64a becomes the scanning line 51 as it is, and the other second metal layer 64b is connected to the pixel electrode 66 made of a transparent conductive material such as ITO (Indium Tin Oxide).
[0025]
Since the liquid crystal device described below is a transmissive type, the pixel electrode 66 is made of an ITO film. However, if the pixel electrode 66 is made of a light reflective material such as Al (aluminum), a reflective liquid crystal device is used. In this case, the backlight device described later is not used. Further, if the pixel electrode 66 is made of a light reflective material such as Al (aluminum) and an opening is formed in a part of the pixel electrode 66, a transflective liquid crystal device can be formed. it can. Further, even if a semi-transmissive / semi-reflective film is formed on the lower layer side of the pixel electrode 66, a semi-transmissive / semi-reflective liquid crystal device can be configured. In such a semi-transmissive / semi-reflective liquid crystal device, an image can be displayed using light from a backlight device at night and the like, and an image can be displayed using outside light during the day.
[0026]
Further, the substrate 17a constituting the element substrate 7a is formed of, for example, quartz, glass, plastic, or the like, similarly to the substrate 17b (see FIGS. 3 and 4) constituting the counter substrate 7a. Here, in the case of the total reflection type, it is not essential that the substrate 17a is transparent. However, in the case of the transmission type as in the present embodiment, or in the above-described transflective / semi-reflective liquid crystal device, It is an essential requirement that the element substrate 17a is transparent.
[0027]
[Configuration of liquid crystal device]
In the element substrate 7a on which the scanning lines 51 and the TFD elements 56 are thus formed, the data lines 52 made of a transparent conductive material such as ITO are formed in a stripe shape, as will be described with reference to FIGS. The element substrate 7a and the counter substrate 7b are bonded to each other so that the pixel electrodes 66 for one column and the one data line 52 are in a positional relationship facing each other. The detailed configuration of the counter substrate 7b will be described later with reference to FIG. 5, FIG. 6, and FIG.
[0028]
3 and 4 are an exploded perspective view and a cross-sectional view of the liquid crystal device, respectively.
[0029]
As shown in FIG. 3 and FIG. 4, the liquid crystal device 1 includes, for example, an FPC (Flexible Printed Circuit) 3 a and 3 b connected to the liquid crystal panel 2 and further guides light to the back side of the liquid crystal panel 2. It is formed by attaching the body 4 and further providing a control substrate 5 on the back side of the light guide 4.
[0030]
In the liquid crystal panel 2, the element substrate 7 a and the counter substrate 7 b are bonded to each other by a sealing material 6 applied in an annular shape to one of these substrates. On the surface of the element substrate 7a that protrudes from the counter substrate 7b, a liquid crystal driving IC 8a is mounted by COG (Chip On Glass) with an ACF (Anisotropic Conductive Film) 9. In addition, a liquid crystal driving IC 8b is COG-mounted by an ACF 9 on a portion of the counter substrate 7b that protrudes from the element substrate 7a.
[0031]
As shown in FIG. 4, a plurality of pixel electrodes 66 described with reference to FIGS. 2A and 2B are formed in a matrix on the inner surface of the element substrate 7a, and an optical sheet is formed on the outer surface thereof. The polarizing plate 12a is stuck. An alignment film 67 for aligning the alignment of the liquid crystal L is formed on the inner surface of the element substrate 7a. This alignment film 67 is formed, for example, by baking after applying a polyimide solution, and the polymer main chain of polyimide is stretched in a predetermined direction by rubbing treatment, so that the liquid crystal L in the liquid crystal L sealed between the substrates is contained. Liquid crystal molecules are coordinated along the stretching direction of the alignment film.
[0032]
As will be described in detail later, a plurality of data lines 52 are formed in a stripe shape on the inner surface of the counter substrate 7b, and a polarizing plate 12b as an optical sheet is attached to the outer surface thereof. The liquid crystal L is sealed in a gap (cell gap) defined by the sealing material 6 between the element substrate 7a and the counter substrate 7b. An alignment film 68 for aligning the alignment of the liquid crystal L is also provided on the inner surface of the counter substrate 7b. Similar to the alignment film 67, the alignment film 68 is formed, for example, by baking after applying a polyimide solution.
[0033]
In FIG. 3, a plurality of terminals 13a are formed on the projecting portion of the element substrate 7a, and these terminals are simultaneously formed when the pixel electrode 66 is formed on the surface of the element substrate 7a. A plurality of terminals 13b are also formed on the protruding portion of the counter substrate 7b, and these terminals are formed at the same time when the data lines 52 are formed on the surface of the counter substrate 7b. A plurality of terminals 22 are provided at the end of the FPC 3b, and these terminals are conductively connected to the terminals 13b of the counter substrate 7b using ACF or the like. A plurality of terminals 23 formed at the other end of the FPC 3 b are connected to terminals (not shown) of the control board 5. In the FPC 3a, a plurality of panel-side terminals 14 are formed at the back surface side end portion, and a plurality of control board side terminals 16 are formed on the surface side at the opposite end portion. Here, a wiring pattern 18 is appropriately formed on the surface of the FPC 3a. The wiring pattern 18 is directly connected to the control board side terminal 16 at one end, and the other end is connected through the through hole 19. It is connected to the panel terminal 14.
[0034]
A diffusion plate 27 is attached to the surface of the light guide 4 on the liquid crystal panel 2 side by sticking or the like, and a reflector 28 is attached to the surface of the light guide 4 opposite to the liquid crystal panel 2 by sticking or the like. Is done. In addition, a plurality of LEDs (Light Emitting Diodes) 21 as light emitting means are arranged to be supported by the LED substrate 38 so as to face the light capturing surface 4 a set on one side surface of the light guide 4.
[0035]
As shown in FIG. 4, the light guide 4 is attached to the back side of the liquid crystal panel 2 with a cushioning material 32 formed of rubber, plastic or the like interposed therebetween. The control board 5 is disposed so as to face the surface of the light guide 4 on which the reflection plate 28 is mounted. A terminal 33 for connecting to an external circuit is formed at the end of the control board 5.
[0036]
In the backlight device of the liquid crystal device 1 configured as described above, when the LED 21 emits light, the light is introduced into the light guide 4, and the introduced light is reflected by the reflecting plate 28 and proceeds toward the liquid crystal panel 2. Then, the light is supplied to the liquid crystal panel 2 in a state of being diffused by the diffusion plate 27 so as to have a uniform strength in a plane. As for the supplied light, the component that has passed through the polarizing plate 12 a on the light guide 4 side is supplied to the layer of the liquid crystal L, and the pixel is further changed in accordance with the change in the voltage applied between the pixel electrode 66 and the data line 52. Each pixel is modulated by the liquid crystal L whose orientation is controlled every time, and the modulated light is passed through the polarizing plate 12b on the display side, thereby displaying an image on the outside.
[0037]
[Configuration of counter substrate 7b]
FIG. 5 is a plan view of the counter substrate used in the liquid crystal device to which the present invention is applied. 6 is a cross-sectional view of the counter substrate shown in FIG. 5 taken along line AA ′, line BB ′, line CC ′, and line DD ′ in FIG. FIGS. 7A and 7B are plan views showing enlarged views of the regions surrounded by the circles F and G of the counter substrate shown in FIG. In FIGS. 5, 7A, and 7B, the region where the sealing material is formed is indicated by a one-dot chain line L1, and the boundary portion between the overcoat layer formation region and the non-formation region is indicated by a two-dot chain line L2. The region where the light shielding film for parting the screen is formed is indicated by a dotted line L3. 17 corresponds to the boundary portion between the overcoat layer formation region and the non-formation region, and the overcoat layer is shown, but the light shielding film and the color filter are formed here. Not shown in the figure.
[0038]
When color display is performed in the liquid crystal device 1, the counter substrate 24b is configured as described below. First, as shown in FIG. 5, in the counter substrate 7a, a plurality of data lines 52 made of striped electrodes are formed in parallel at a predetermined interval in a region defined by the sealing material 6. At the same time, a wiring portion 520 extends from each of the data lines 52 toward the mounting region 80b of the liquid crystal driving IC chip.
[0039]
Further, the counter substrate 7a has cross sections (cross sections AA ', BB', CC ', and DD' in FIG. 5) at the respective positions of the counter substrate 7b in FIG. As shown, a light shielding film 43 called a black matrix, red (R), green (G), and blue (B) color filters 40R, 40G, and 40B, an insulating overcoat are provided on the surface side of the transparent substrate 17b. The layer 45, the data line 52, and the alignment film 68 are stacked in this order. In addition, a light shielding film 45 for parting the screen is formed along the sealing material 6 inside the area surrounded by the sealing material 6, and the area surrounded by the light shielding film 45 is an image display area where an image is displayed. It becomes. Accordingly, the color filters 40R, 40G, and 40B and the light shielding film 43 are formed only inside the region surrounded by the light shielding film 45 for screen parting. As can be seen from FIG. 4, the light shielding film 43 is formed in a region not facing the pixel electrode 66 formed on the element substrate 7a, and the color filters 40R, 40G, and 40B are formed in a region facing the pixel electrode 66. Is formed.
[0040]
In FIG. 6 again, the overcoat layer 45 is composed of a thick organic insulating film or inorganic insulating film for eliminating unevenness caused by the color filters 40R, 40B, and 40B formed on the lower layer side, and the data is formed on the upper layer side. A line 52 is formed. The overcoat layer 45 is formed in a region of the surface of the counter substrate 7 b that is wider than the region surrounded by the screen light-shielding film 45 but narrower than the region surrounded by the sealing material 6. In contrast, in the data line 52, one end portion 451 protrudes from the formation region 45a of the overcoat layer 45, while the seal material 6 is further formed from the formation region 45a of the overcoat layer 45 on the other side. The liquid crystal driving IC 8b extends through the region to the region where the COG mounting is performed. For this reason, the data line 52 extends over both the formation region 45a and the non-formation region 45b of the overcoat layer 45, as shown in FIGS. Here, since the overcoat layer 45 is made of, for example, a thick insulating film of 2000 nm to 3000 nm, a large step 450 is formed at the boundary between the formation region 45 a and the non-formation region 45 b of the overcoat layer 45. A data line 52 passes above.
[0041]
Here, in the data line 52, the electrode width is narrower in the portion passing over the step 450 than in the portion passing over the formation region 45a of the overcoat layer 45. That is, the portion of the data line 52 that passes over the step 450 is wider than both the portion that passes over the formation region 45a of the overcoat layer 45 and the portion that passes over the non-formation region 45b of the overcoat layer 45. Is a narrow constricted portion 525. For this reason, when the liquid crystal device 1 is manufactured by the method described below, the data line 52 is not short-circuited on the step 450.
[0042]
[Method of Manufacturing Liquid Crystal Device 1 and Counter Substrate 7b]
FIG. 8 is a process diagram showing a method for manufacturing the liquid crystal device 1 of the present embodiment. 9 and 10 are process cross-sectional views illustrating a manufacturing method of the counter substrate 7b used in the liquid crystal device 1 of the present embodiment.
[0043]
As shown in FIG. 8, in manufacturing the liquid crystal device 1 and the liquid crystal panel 2, from the element substrate forming process including the active element forming process P11 to the sealing material printing process P15, and the light shielding film forming process P21 to the rubbing process P26. The counter substrate forming step is performed separately.
[0044]
First, in forming the element substrate 7a, the scanning lines 51 and the TFD elements 56 are formed on the surface of the substrate 17a in the active element forming step P11, and then the pixel electrode 66 is formed in the pixel electrode forming step P12. Next, after an alignment film 67 is formed by forming polyimide, polyvinyl alcohol, etc. on the surface of the substrate 17a in a uniform thickness in the alignment film process P13, a rubbing process is performed on the alignment film 67 in a rubbing process process P14. Other alignment treatment is performed. Next, the sealing material 6 is annularly applied by a dispenser, screen printing, or the like in the sealing material printing step P15. An opening 6a for liquid crystal injection is formed in a part of the sealing material 6.
[0045]
On the other hand, in forming the counter substrate 7b, first, in the light shielding film forming step P21, as shown in FIG. 9A, the light shielding films 43 and 44 are applied to a predetermined region on the surface of the transparent substrate 17b using a photolithography technique. Form. Next, in the color filter forming step P22, as shown in FIG. 9B, color filters 40R, 40G, and 40B are formed. Such color filters 40R, 40G, and 40B are formed by flexographic printing, a photolithography technique, an inkjet method, or the like. Next, in the overcoat layer forming step P23, as shown in FIG. 9C, an insulating overcoat layer 45 is formed using flexographic printing or photolithography technology. Next, in the data line forming step P24, a stripe electrode, that is, the data line 52 is formed from the ITO film.
[0046]
First, as shown in FIG. 9D, an ITO film 52 'is formed on the entire surface of the transparent substrate 17b by sputtering. Next, as shown in FIG. 10 (a), a photosensitive resist 600 is applied to the entire surface of the ITO film 52 ', and the photosensitive resist 600 is exposed and developed through an exposure mask 610. As shown in (b), a resist mask 601 is formed. Next, the ITO film 52 ′ is patterned through the resist mask 601 to form stripe-shaped data lines 52 as shown in FIG.
[0047]
Next, after an alignment film 68 having a uniform thickness is formed on the data lines 52 and the like with polyimide or the like in the alignment film formation process P25, a rubbing process or the like is performed on the alignment film 68 in the rubbing process P26. An orientation process is performed. Thereby, the counter substrate 7b is completed.
[0048]
Such a process is performed in a state of a large mother substrate capable of obtaining a large number of element substrates 7a and counter substrates 7b. Therefore, after finishing each of the above steps, the mother substrates are bonded to each other with the sealing material 6 interposed therebetween (bonding step P31), and then the sealing material 6 is cured by ultraviolet curing or other methods (sealing material curing step). P32). As a result, an empty panel structure including a plurality of liquid crystal devices is formed. Thereafter, a cutting groove is formed at a predetermined position of the empty panel structure, and the panel structure is cut into a strip shape based on the scribe groove (primary breaking step P33). Thereby, a strip-shaped empty panel structure in which the liquid crystal injection opening 6a of the sealing material 6 of each liquid crystal panel is exposed to the outside is formed. Next, after the liquid crystal is injected into the inside of the panel under reduced pressure from the exposed liquid crystal injection opening 6a, each opening 6a is sealed with resin or the like (liquid crystal injection / injection port sealing step P34). Then, after forming a cutting groove again in the panel structure, a plurality of liquid crystal panels are cut out by cutting the strip-shaped panel structure along the cutting groove (secondary break process P35). As shown in FIG. 4, polarizing plates 12a and 12b are attached to the liquid crystal panel 2 thus manufactured (polarizing plate attaching step P17). After that, as shown in FIG. 3, the liquid crystal driving ICs 8a and 8b and the control board 5 are mounted, and the FPCs 3a and 3b are connected to complete the liquid crystal device 1 (mounting process P37).
[0049]
[Effect of this embodiment]
In such a manufacturing process, in the data line forming process P24 for forming the data line 52 on the counter substrate 7b, when exposure is performed as shown in FIG. 10A, the formation area 45a of the overcoat layer 45 is not formed. Due to the influence of the shadow caused by the step 450 formed at the boundary with the region 45b, the resist 600 in the portion that should be originally exposed is not exposed. 10 As shown by a dotted line L4 in FIG. 5B, when an extra resist 601 remains at a position where the ITO film 600 is to be removed, when the ITO film 52 ′ is patterned, in the portion where the extra resist 601 remains, As shown in FIGS. 7A, 7B, and 10C, an extra ITO film 52 ″ may remain between the data lines 52. Also, there is an abnormality in the exposure of the resist 600. Even if it does not occur, when the ITO film 52 ′ is patterned by dry etching, an extra ITO film 52 ″ may remain between the data lines 52 due to a shadow caused by the step 450. Moreover, when the ITO film 52 'is formed by sputtering, the color filters 40R, 40G, and 40B made of an organic substance are already formed on the lower layer side. Therefore, in view of the heat resistance of the organic substances constituting the color filters 40R, 40G, and 40B, The ITO film 52 'cannot be sputter-formed under a very high temperature condition, and the ITO film 52' sputter-formed under such a low temperature condition cannot be patterned with high accuracy. However, in this embodiment, the data line 52 is compared with a portion where the portion passing over the step 450 passes over the formation region 45a of the overcoat layer 45 and a portion passing over the non-formation region 45b of the overcoat layer 45. As a result, the constricted portion 525 has a narrow width. Data line 52 will not be short-circuited. Therefore, the pitch of the data lines 52 can be reduced.
[0050]
In addition, when the width of the data line 52 is reduced, the electrical resistance of this portion increases. However, in this embodiment, a constricted portion 525 is provided on the step 450 where a short circuit is likely to occur, and the other portion is the overcoat layer 45. The width is substantially equal to the portion passing through the formation region 45a. Therefore, an increase in electrical resistance of the data line 52 can be minimized.
[0051]
[Other embodiments]
FIGS. 11A and 11B are plan views showing enlarged positions corresponding to the circles F and G in FIG. 5 on another counter substrate used in the liquid crystal device to which the present invention is applied. 12A to 12D are cross-sectional views showing the configuration of data lines in each counter substrate used in the liquid crystal device to which the present invention is applied.
[0052]
In the above embodiment, the portion of the data line 52 that passes over the step 450 is both the portion that passes over the formation region 45a of the overcoat layer 45 and the portion that passes over the non-formation region 45b of the overcoat layer 45. Compared with the narrowed portion 525, the counter substrate 7b shown in FIGS. 11 (a) and 11 (b) does not form the portion of the data line 52 that passes over the step 450 and the overcoat layer 45. The width of the wiring portion 520 that passes through the region 45b is narrower than the portion that passes over the formation region 45a of the overcoat layer 45. Since the other configuration is the same as that of the above-described embodiment, common portions are denoted by the same reference numerals, and description thereof is omitted.
[0053]
Even in this configuration, even if an extra ITO film 52 ″ remains between the data lines 52 on the step 450, the data lines 52 will not be short-circuited, so the pitch of the data lines 52 can be reduced. The wiring portion 520 extending from the data line 52 and passing over the non-formation region 45b of the overcoat layer 45 is drawn obliquely so as to converge toward the IC mounting region. If 520 is formed with a narrow width, a large number of wirings can be formed in a narrow region, which is advantageous when the number of stripe electrodes 52 is increased.
[0054]
In any of the above forms, as shown in FIG. 11A, the data line 52 and the wiring portion 520 are made of an ITO film (metal oxide film). As shown in FIGS. 12B, 12C, and 12D, a metal oxide film such as an ITO film is used for a portion where the electrode width is narrower than a portion passing over the formation region 45a of 45. If a structure having a multilayer structure with the metal film M is employed, the electrical resistance of the portion where the electrode width is narrow can be lowered. Here, the data line 52 shown in FIG. 12B has a structure in which a metal film M is laminated on a metal oxide film such as an ITO film. A data line 52 shown in FIG. 12C has a structure in which a metal film M is laminated under a metal oxide film such as an ITO film. In this case, when the adhesion of the metal film M to the base is weak, or when the elution of impurities from the metal film M to the liquid crystal becomes a problem, as shown in FIG. A metal oxide film, a metal film M, and a metal oxide film such as an ITO film may be stacked in this order, and the upper and lower ITO films may be formed wider than the metal film M to form the metal film M. If it is completely covered with the ITO film, the elution of impurities from the metal film M and the problem of adhesion can be solved. Here, as the metal film, a simple silver, an alloy containing platinum (Pt) or copper (Cu) in addition to about 98% silver, a silver-gold-copper alloy, a silver-ruthenium-copper alloy, or the like can be used. .
[0055]
In any of the above embodiments, the active matrix type liquid crystal device 1 using a TFD element as an active element has been described as an example. However, if the electro-optical device is formed in a stripe shape on a substrate, a passive matrix can be used. Various modifications can be made within the scope of the invention described in the claims, such as the present invention may be applied to a liquid crystal device of a type or other electro-optical devices.
[0056]
[Embodiment of Electronic Device]
FIG. 13 shows an embodiment in which the liquid crystal device according to the present invention is used as a display device of various electronic devices. The electronic device shown here includes a display information output source 70, a display information processing circuit 71, a power supply circuit 72, a timing generator 73, and a liquid crystal device 74. The liquid crystal device 74 includes a liquid crystal display panel 75 and a drive circuit 76. As the liquid crystal device 74 and the liquid crystal panel 75, the liquid crystal device 1 and the liquid crystal panel 2 described above can be used.
[0057]
The display information output source 70 includes a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a storage unit such as various disks, a tuning circuit that tunes and outputs a digital image signal, and the like, and is generated by a timing generator 73. Display information such as an image signal in a predetermined format is supplied to the display information processing circuit 71 based on the various clock signals.
[0058]
The display information processing circuit 71 includes various well-known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, a clamp circuit, and the like, executes processing of input display information, and outputs the image. The signal is supplied to the driving circuit 76 together with the clock signal CLK. The drive circuit 76 is a general term for the scanning line drive circuit 57, the data line drive circuit 58, the inspection circuit, and the like in FIG. The power supply circuit 72 supplies a predetermined voltage to each component.
[0059]
FIG. 14 shows a mobile personal computer which is an embodiment of an electronic apparatus according to the present invention. The personal computer shown here has a main body 82 having a keyboard 81 and a liquid crystal display unit 83. The liquid crystal display unit 83 includes the liquid crystal device 1 described above.
[0060]
FIG. 15 shows a mobile phone which is another embodiment of the electronic apparatus according to the invention. The cellular phone 90 shown here has a plurality of operation buttons 91 and the liquid crystal device 1.
[0061]
【The invention's effect】
As described above, in the electro-optical device according to the present invention, a large step is formed at the boundary between the formation region and the non-formation region of the insulating film formed as an overcoat layer or the like, and the striped electrode passes over the step. Even in such a case, the plurality of striped electrodes have a narrower electrode width compared to a portion passing over the step and over a region where the insulating film is formed. For this reason, even when an exposure abnormality occurs due to a shadow due to a step during exposure for forming a resist mask for patterning the stripe-shaped electrode, and an extra conductive film remains between the stripe-shaped electrodes, the step There is no short circuit between the striped electrodes. In addition, when dry etching for patterning the stripe electrode is performed, even if an etching abnormality occurs due to a shadow caused by the step, and an extra conductive film remains between the stripe electrodes, the stripe is formed on the step. The electrode-like electrodes are not short-circuited. Therefore, the pitch of the striped electrodes can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing an electrical configuration of a liquid crystal device.
2A and 2B are respectively a plan view of one pixel in an element substrate among a pair of substrates sandwiching a liquid crystal layer in a liquid crystal panel, and II ′ in FIG. 2A. It is line sectional drawing.
FIG. 3 is an exploded perspective view of a liquid crystal device.
FIG. 4 is a cross-sectional view of a liquid crystal device.
FIG. 5 is a plan view of a counter substrate used in a liquid crystal device to which the present invention is applied.
6 is a cross-sectional view when the counter substrate shown in FIG. 5 is cut along the lines AA ′, BB ′, CC ′, and DD ′ in FIG. 5;
7A and 7B are plan views showing enlarged views of regions surrounded by a circle F and a circle G of the counter substrate shown in FIG. 5, respectively.
FIG. 8 is a process diagram illustrating a method of manufacturing a liquid crystal device to which the present invention is applied.
9A to 9D are process cross-sectional views illustrating a manufacturing method of the counter substrate shown in FIG.
10A to 10C are process cross-sectional views of processes performed subsequent to the process illustrated in FIG. 9 in the process for manufacturing the counter substrate illustrated in FIG. 5;
11A and 11B are plan views showing enlarged positions corresponding to the circles F and G in FIG. 5 on another counter substrate used in the liquid crystal device to which the present invention is applied, respectively. is there.
FIGS. 12A to 12D are cross-sectional views showing the configuration of data lines in each counter substrate used in the liquid crystal device to which the present invention is applied;
FIG. 13 is a block diagram showing a configuration of various electronic devices using the liquid crystal device according to the invention.
FIG. 14 is an explanatory diagram showing a mobile personal computer as an embodiment of an electronic apparatus using the liquid crystal device according to the invention.
FIG. 15 is an explanatory diagram of a mobile phone as an embodiment of an electronic apparatus using the liquid crystal device according to the invention.
FIG. 16 is a plan view of a counter substrate used in a conventional liquid crystal device.
17 is a cross-sectional view of the counter substrate shown in FIG. 16 taken along line AA ′, BB ′, CC ′, and DD ′ in FIG. 16;
FIGS. 18A and 18B are plan views showing enlarged views of regions surrounded by a circle F and a circle G of the counter substrate shown in FIG. 16, respectively.
19 is a process cross-sectional view illustrating the manufacturing method of the counter substrate illustrated in FIG. 16;
[Explanation of symbols]
1 Liquid crystal device (electro-optical device)
2 LCD panel
6 Sealing material
7a Element substrate
8a, 8b Liquid crystal drive IC
17a Substrate constituting the element substrate
17b Transparent substrate constituting the counter substrate
40R, 40G, 40B color filter
43, 44 Light-shielding film
45 Overcoat layer (insulating film)
45a Overcoat layer formation region
45b Non-formation region of overcoat layer
51 scan lines
52 Data line (stripe electrode)
52 'ITO film
52 "extra ITO film
53 pixels
54 Liquid crystal layer
56 TFD element
57 Scanning line drive circuit
58 Data line drive circuit
66 Pixel electrode
450 steps
520 Wiring part
525 Constricted part
600 photoresist
601 resist mask
610 Exposure mask
601 'Extra resist mask

Claims (11)

An insulating film is formed in a predetermined region on the first substrate holding the electro-optic material, and a plurality of stripes are formed on both the insulating film forming region and the non-forming region on the upper layer side of the insulating film. In an electro-optical device in which electrodes extend in parallel,
On the lower layer side of the striped electrode, a step is formed in a portion corresponding to the boundary between the formation region of the insulating film and the non-formation region,
2. The electro-optical device according to claim 1, wherein the plurality of striped electrodes have an electrode width that is narrower at a portion passing over the step than at a portion passing through the insulating film formation region.   2. The part of the plurality of striped electrodes according to claim 1, wherein a portion passing over the step is compared with both a portion passing over the insulating film forming region and a portion passing over the non-forming region of the insulating film. An electro-optical device characterized by a narrow constricted portion.   2. The width of the plurality of striped electrodes according to claim 1, wherein a portion passing over the step and a portion passing through the non-formation region of the insulating film are wider than a portion passing through the formation region of the insulating film. An electro-optical device that is narrowed.   4. The electro-optical device according to claim 1, wherein the insulating film is an overcoat film for flattening unevenness formed by a color filter formed on a lower layer side of the insulating film. apparatus.   5. The electro-optical device according to claim 1, wherein the stripe electrode is formed by patterning a sputtered conductive film using a photolithography technique. 6. The electro-optical device according to claim 1 , wherein the stripe electrode is formed of a conductive metal oxide film. 6. The electro-optical device according to claim 1 , wherein the stripe electrode is made of an ITO film. In any of claims 1 to 7, of the stripe-shaped electrode, the portion where the electrode width compared to the portion through a forming region on the insulating film becomes narrow, and the metal oxide film and the metal film An electro-optical device having a multilayer structure.   9. The method according to claim 1, wherein a region surrounded by the sealing material is provided between the first substrate and the second substrate bonded to the first substrate through the sealing material. An electro-optical device, wherein a liquid crystal as the electro-optical material is held. 8. The portion of the striped electrode in which an electrode width is narrower than a portion passing over a region where the insulating film is formed is formed between the metal oxide film and the metal film. An electro-optical device having a multilayer structure and lowering the electrical resistance of a portion where the electrode width is narrow. An electronic apparatus comprising the electro-optical device as defined in claim 1 as a display unit.

Images