JP2001092382A - Mask for formation of electrode pattern and production of electro-optic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electro-optic device having an electrode pattern having an electrode the end of which is disposed in a driving region, and to provide a production method of the device so that when the electrode pattern is misaligned to the counter electrode pattern, the area of the pixel region is hardly increased or decreased and production of display defects can be reduced. SOLUTION: A photosensitive resist layer 28 (not shown in the figure) formed on a transparent conductive film 17 is exposed by using a light-shielding mask 29 and developed to form a resist pattern 28a. Then, the film is etched by using a mixture etching liquid such as sulfuric acid, nitric acid and hydrochloric acid. The opening 29a of the light-shielding mask 29 is formed a size larger than the planar form of the designed segment electrode 11a, 11b, and in the region corresponding to the corners 11a-2, 11b-2, the opening is formed as more expanded outward from the position corresponding to the outer edge of the segment electrode 11a, 11b than in other positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask for forming an electrode pattern and a method of manufacturing an electro-optical device. The present invention relates to a technique for forming an electrode pattern.

[0002]

2. Description of the Related Art In general, a liquid crystal display device as a kind of electro-optical device has a structure including a plurality of divided drive regions in a display drive region, such as a divided matrix display system. In the divided matrix display method, for example, two divided drive regions are configured by dividing a scan electrode (or a common electrode) into two groups and allocating independently separated display electrodes (segment electrodes). Since each of the divided drive regions is scanned separately, if the number of pixels is the same, an operation margin in time-division drive can be increased as compared with a liquid crystal device having a normal single drive region.

FIG. 4 shows a liquid crystal device of this type, which is called a split matrix display system or a two-screen drive panel. In this liquid crystal device 10, transparent substrates 11 and 12 are bonded together via a sealing material 13.
At the upper and lower ends of the transparent substrate 11, overhanging regions 11 s and 11 t are provided, respectively, which extend beyond the transparent substrate 12. At the right end of the transparent substrate 12 in the figure, an overhang region 12 s that extends beyond the transparent substrate 11 is provided.

On the inner surface of the transparent substrate 11, a number of segment (display) electrodes 11a and 11b extending vertically in the figure are formed in parallel. The segment electrode 11a is formed on the upper half of the transparent substrate 11 in the figure, and the segment electrode 11b
Is formed in the lower half of the transparent substrate 11 in the figure. The segment electrodes 11a and 11b are drawn out as wirings 11c and 11d on the surfaces of the overhang regions 11s and 11t, respectively, and are electrically connected to the wiring patterns of the flexible wiring boards 14 and 15 connected to the overhang regions 11s and 11t. Have been. On the other hand, a large number of common (scanning) electrodes 12a are formed on the inner surface of the transparent substrate 12 and extend in the left and right directions in the figure. It is conductively connected to the wiring pattern of the wiring board 16.

In the above structure, liquid crystal is sealed in a liquid crystal sealing area surrounded by a sealing material 13, and the segment electrode 1 is sealed in the liquid crystal sealing area.
A portion where 1a, 11b and the common electrode 12a intersect in plan is a pixel region, and a display drive region E in which the pixel regions are arranged in a matrix is provided.

In such a divided matrix type liquid crystal device, the segment electrode 1 is provided in the display drive area E.
The ends of 1a and 11b are arranged. In the structure shown in FIG. 4, there is an end facing region F in which the end of the segment electrode 11a and the end of the segment electrode 11b face each other. The vicinity of the end facing region F is shown in an enlarged scale in FIG. As shown in FIG. 5, in the end facing region F, the end 11a-1 of the segment electrode 11a and the end 11b-1 of the segment electrode 11b face each other with a slight gap therebetween.

Generally, in the step of forming the segment electrodes 11a and 11b, as shown in FIG. 6A, a transparent conductive film 17 is formed on a transparent substrate 11, and a photosensitive resist layer 1 is formed thereon.
After applying and forming the photosensitive resist layer 8, the photosensitive resist layer 18 is exposed through a light-shielding mask 19 and developed to form a predetermined resist pattern 18a as shown in FIG. And
By etching the transparent conductive film 17 using this resist pattern 18a as an etching mask,
As shown in FIG. 6C, the segment electrodes 11a and 11b having a shape corresponding to the resist pattern 18a are formed.

[0008]

However, in the conventional liquid crystal device described above, when the transparent substrate 11 and the transparent substrate 12 are bonded to each other via the sealing material 13, a certain degree of substrate displacement often occurs. . At this time, as shown in FIG. 5, the electrode width Ew of the segment electrode 11a, 11b or the common electrode 12a (for example, 200 to 300 μm).
m), the gap Eg between the electrodes (for example, 30 to 50 μm)
Since m) is small, when the substrate shift occurs, the common electrode 12a is shifted with respect to the segment electrodes 11a and 11b, for example, in the vertical direction in the figure. At this time, since the end portions 11a-1 and 11b-1 of the segment electrodes 11a and 11b have the corner portions 11a-2 and 11b-2 which are rounded by side etching at the time of the above patterning, the substrate shifts. In some cases, the corners 11a-2 and 11b-2 may be arranged so as to overlap the common electrode 12a in a plane as shown by a dashed line in FIG.
An electric field different from a normal applied electric field in the pixel region is applied to a portion δ1 where the portions where the segment electrodes 11a and 11b are missing due to the rounded shapes of the corners 11a-2 and 11b-2 and the common electrode 12a overlap. The display state becomes different from that of the surrounding pixel area, for example, a display defect, for example, a non- lighting area (a region that is always in a transmission state) due to the state. In particular, in the case of the liquid crystal device of the divided matrix display system, the display defects generated as described above are arranged in a line along the boundary of the divided drive area (extending in the horizontal direction in FIGS. 4 and 5). Therefore, even if δ1 is a very small area difference, it is conspicuous as a linear display defect, and the display quality is greatly impaired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electro-optical device having an electrode pattern having electrodes whose ends are arranged in a driving area. It is an object of the present invention to provide a manufacturing method in which the area of a pixel region does not easily increase or decrease even if it is displaced from a pattern, and the occurrence of display defects can be reduced.

[0010]

According to the present invention, there is provided an electrode pattern forming mask comprising: a first electrode and a second electrode which are not connected to each other on a substrate; In the mask for forming an electrode pattern used to form the first electrode or the second electrode, the first electrode or the second electrode has a corner formed at a portion where the first electrode or the second electrode is opposed to the first electrode or the second electrode. At a corresponding position, the corner portion has a pattern shape shifted inward or outward with respect to the shape of the corner portion.

According to the present invention, the pattern corresponding to the corner portion of the electrode has a pattern shape shifted inward or outward with respect to the shape of the corner portion. Is set so as to reduce the occurrence of defective display due to a pattern formation error in the corner portion of the electrode, and the occurrence of defective display and display defects can be reduced.

Further, the electrode pattern forming mask of the present invention provides an electrode pattern used for forming a first electrode and a second electrode, which are not connected to each other, on a substrate such that ends of the electrodes face each other. In the forming mask, the first electrode or the second electrode is formed by etching, and the first electrode or the second electrode has a corner formed at a portion facing the first electrode or the second electrode, and the electrode pattern forming mask is formed. Is characterized by having a pattern shape projecting outward with respect to the shape of the corner portion at a position corresponding to the corner portion.

In the present invention, it is preferable that the mask for forming an electrode pattern has a pattern shape in which a deviation from the shape of the corner portion is greatest at a position corresponding to the corner portion.

According to this invention, at the position corresponding to the corner of the mask for forming an electrode pattern, the deviation from the shape of the corner is formed to be the largest, so that the corner protruding from the periphery is formed. Since the shape can be compensated for in response to an increase in the pattern formation error in the portion, display defects and defects which are likely to occur in the corner can be further reduced.

In the present invention, the mask for forming an electrode pattern has, at a position corresponding to the corner portion, a projecting contour portion protruding from a position corresponding to the corner portion in an extending direction or a width direction of the electrode. Is preferred.

According to the present invention, the electrode portions corresponding to the protruding contours are easily lost during pattern formation, but the presence of the protruding contours causes a pattern forming error in the corners to be formed inside the protruding contours. As it can be made difficult, it is possible to reliably secure the corner shape,
Since the protruding contour portion protrudes in the extending direction or the width direction of the electrode, it can be formed so that the corner portion remains reliably during patterning.

In the present invention, the first electrode or the second electrode is formed by forming a photosensitive resist film on an electrode layer formed on the substrate by using a constituent material of the electrode, and forming the photosensitive resist film on the substrate. Exposure and development to form a resist pattern,
The first or second electrode is formed by etching the electrode layer using the resist pattern, and is preferably an exposure mask for the photosensitive resist film.

Since an electrode pattern is formed by etching using a resist pattern formed using an electrode pattern forming mask as an exposure mask, exposure errors and pattern formation errors due to side etching are liable to occur. According to the present invention, even if the pattern formation error is large, the error can be compensated by providing the pattern shape deviation, so that a great effect can be exhibited.

According to a method of manufacturing an electro-optical device of the present invention, there is provided a method of manufacturing an electro-optical device in which an electrode for applying a voltage to an electro-optical material is formed on a substrate, wherein the constituent material of the electrode is used on the substrate. Forming an electrode layer, forming a photosensitive resist film on the electrode layer, exposing the photosensitive resist film, and developing to form a resist pattern,
Forming a first electrode and a second electrode that are not connected to each other on the substrate by etching using the resist pattern such that ends of the electrodes face each other;
Wherein the first electrode or the second electrode has a corner formed at a portion facing the first electrode or the second electrode, and the exposure includes an inner side with respect to a shape of the corner at a position corresponding to the corner. Alternatively, an exposure mask having a pattern shape shifted outward is used.

In the present invention, it is preferable that the mask for forming an electrode pattern has a pattern shape in which a deviation from the shape of the corner portion is greatest at a position corresponding to the corner portion.

In the present invention, the electro-optical device includes a plurality of divided drive units in a display drive area thereof, and an opposing portion between the first electrode and the second electrode is provided at a boundary position between the divided drive units. It is preferable that it is formed.

When a portion having a different display state occurs due to a pattern formation error in a portion where the two electrodes face each other, a display defect or a display defect appears linearly at a boundary position between the divided driving portions, so that the display is easily noticeable and the display quality is reduced. According to the present invention, display defects and display defects at the relevant portion can be reduced, while the display quality is greatly reduced.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method for manufacturing an electrode pattern forming mask and an electro-optical device according to the present invention will be described in detail with reference to the accompanying drawings. Although the embodiments described below relate to a liquid crystal device of a split matrix type, the present invention is not limited to such a liquid crystal device, and various electro-optical devices (ends of an electrode pattern disposed in a driving region thereof) are provided. For example, the present invention can be applied to an electroluminescent display device.

FIG. 1 shows an electrode pattern (including a plurality of segment (display) electrodes 11a and 11b) opposed to each other in the vicinity of an end facing region F (see FIG. 4) in a liquid crystal device of a divided matrix system according to the present invention. FIG. 3 is an enlarged plan view showing the plan shapes of a pattern and a counter electrode pattern (a pattern including a plurality of common (scanning) electrodes 12a).
In the present embodiment, the overall configuration of the liquid crystal device is the same as the configuration shown in FIG.

In the liquid crystal device of the present embodiment, the end portions 11a-1 and 11b-1 of the segment electrodes 11a and 11b.
Has corners 11a-2 and 11b-2 which are less rounded than the conventional shape shown in FIG. 5, that is, have a smaller radius of curvature. Such shapes of the end portions 11a-1 and 11b-1 can be obtained by patterning using a mask (a resist pattern 28a and a light-shielding mask 29 described later) having a shape shown by a dashed line in the drawing.

FIG. 2 shows a light-shielding mask (exposure mask for exposing a photosensitive resist) 2 used for patterning the segment electrodes 11a and 11b in this embodiment.
9 is an enlarged plan view showing an end portion of the resist pattern 9 and a resist pattern 28a, that is, a portion facing the segment electrodes 11a and 11b. The patterning step in this embodiment is the same as the method shown in FIG. 6, and the photosensitive resist layer 28 (not shown) formed on the transparent conductive film 17 shown in FIG.
Exposure is performed using the light-shielding mask 29 shown in FIG.
Forming a resist pattern 28a shown in FIG.
Thereafter, etching is performed using, for example, a mixed etching solution of sulfuric acid, nitric acid, and hydrochloric acid. At this time, the light shielding mask 2
The outline shape (inner edge shape) of the opening 29a of FIG. 9 is slightly larger than the planar shape of the segment electrodes 11a and 11b shown by the two-dot chain line, and the corners 11a-2 and 11b-2.
In the vicinity of the portion corresponding to the above, a shape is provided which protrudes largely outward with respect to a position corresponding to the outer edge of the designed segment electrode 11a, 11b than other portions.
In the present embodiment, the photosensitive resist layer 28 uses a negative resist, and the contour shape (outer edge shape) of the resist pattern 28a is developed into a shape substantially equal to the opening shape of the opening 29a. In addition, the contour shape (outer edge shape) of the portion corresponding to the corners 11a-2 and 11b-2 in the resist pattern 28a is shifted most greatly from the outer edge shape of the corner to be formed than the periphery thereof. Designed for

When a positive resist is used as the photosensitive resist layer, it is necessary to use a light-shielding mask in which the relationship between the light-shielding portion and the opening is reversed. Outline shape of the opening (inner edge shape)
Is slightly smaller than the position corresponding to the outer edges of the segment electrodes 11a and 11b (in the direction in which the opening area is reduced), and is closer to the corners 11a-2 and 11b-2 than to other portions. Also, the segment electrode 11
It is necessary to have a shape that is largely drawn inward (that is, in a direction in which the opening area decreases) with respect to the position corresponding to the outer edge of a, 11b.

As shown in FIG. 2B, by etching the transparent conductive film 17 through the resist pattern 28a, the transparent conductive film 17 not covered with the resist pattern 28a is removed by etching. ,
Side etching occurs from the outer edge of the resist pattern 28a, and the boundary portion of the transparent conductive film 17 below the outer edge of the resist pattern 28a is also etched toward the center of the resist pattern 28a. Although the amount of side etching varies depending on the composition of the etchant, the etching time, and the like, the etching rate is generally higher at the corners of the pattern where the ratio of the surface area in contact with the etchant is larger than at other portions.

Under the above situation, in this embodiment, the contour of the resist pattern 28a is
From the position corresponding to the outer edge of 1a, 11b, it is formed to be larger by a distance corresponding to the amount of side etching considered or assumed, and particularly to the corners 1 of the segment electrodes 11a, 11b.
The portions corresponding to 1a-2 and 11b-2 are formed so as to protrude most outward (that is, shift or overhang). For this reason, even if the side etching occurs, the segment electrodes 11a and 11b to be formed are formed.
Is an ideal shape, that is, the corners 11a-
The erosion of 2, 11b-2 is small, and the radius of curvature of the contour shape is small.

As a result, the segment electrode 11 shown in FIG.
The a and 11b have substantially the same width at the tips of the ends 11a-1 and 11b-1. For this reason, in the substrate bonding step, the transparent substrates 11 and 12 are bonded to each other so as to be shifted from each other from a predetermined position, so that the positions of the segment electrodes 11a and 11b and the common electrode 1
Even if the position of 2a is shifted in the direction of extension of the segment electrodes 11a and 11b (vertical direction in FIG. 1), the corner 11a-
Ends 11a-1 and 11a-1 due to loss of 2, 11b-2
Since a region where good control cannot be performed due to the potential of the segment electrodes 11a and 11b does not occur at the corners of the pixel regions A and B adjacent to b-1, the linear shape along the facing end region F is eliminated. Display defects are less likely to occur.

In this embodiment, a resist pattern 28a is formed by photolithography using the light-shielding mask 29 as an exposure mask as a patterning method of the electrode pattern. In this case, the light shielding mask 29 also corresponds to the electrode pattern forming mask of the present invention, and the resist pattern 28a also corresponds to the electrode pattern forming mask of the present invention.

In the above embodiment, the segment electrodes 11a and 11b are formed using a mask shape as shown in FIG. 2, but the present invention is not limited to such a shape, In order to prevent the corners 11a-2 and 11b-2 of the 11a and 11b from being eroded, any mask shape having a planar shape that compensates for the erosion may be used. For example, FIGS. It is also possible to form using a mask shape having various contour shapes shown in c). It should be noted that the mask shape shown in FIG. 3 is based on the premise that the mask has a shape that covers the electrode layer, similarly to the above-described resist pattern 28a.

The mask shape 31 shown in FIG. 3A corresponds to the corners 11a-2 and 11b-of the segment electrodes 11a and 11b.
2 is provided with a protruding portion 31a having a shape protruding in the direction of extension of the segment electrodes 11a and 11b from the position corresponding to the portion 2. The electrode portion hidden under the protruding portion 31a is almost disappeared during etching, but the protruding portion 31a , The corners of the mask are separated from the corners of the electrode ends where the masks are to be formed, so that the corners 11a-2 and 11b-2 are hardly eroded.

The mask shape 32 shown in FIG. 3B corresponds to the corners 11a-2 and 11b-of the segment electrodes 11a and 11b.
2 has a shape including a protruding portion 32a protruding from a position corresponding to 2 in a direction parallel to the segment electrodes 11a and 11b (a direction orthogonal to the extending direction, that is, a width direction of the segment electrodes 11a and 11b). This protruding part 3
Although the electrode portion hidden under 2a almost disappears during the etching, the presence of the protruding portion 32a causes the corner of the mask to be separated from the corner of the electrode end where the mask is to be formed. Erosion is almost eliminated.

The mask shape 33 shown in FIG. 3 (c) corresponds to the corners 11a-2, 11b-of the segment electrodes 11a, 11b.
In the vicinity of the position corresponding to No. 2, there is provided an overhanging portion 33 a protruding outward with a substantially constant width in both the extending direction and the parallel direction of the segment electrodes.
Although the side etching occurs even below, the amount of erosion of the corners 11a-2 and 11b-2 is reduced by the presence of the overhang portion 33a.

The mask for forming an electrode pattern and the electro-optical device according to the present invention are not limited to the illustrated examples described above, and various modifications can be made without departing from the scope of the present invention. It is. For example, in the above embodiment, a photo-etching method is used as a patterning method for forming an electrode pattern. However, for example, an electrode pattern such as an ITO film or a NESA film is directly formed on a substrate using an electrode pattern forming mask. May be formed. Even in such a case, since the corners of the electrode pattern tend to be rounded with respect to the mask shape, a display failure near the end of the electrode portion in the display drive region can be achieved by using the same configuration as the above mask shape. And display defects can be suppressed.

[0037]

As described above, according to the present invention,
By having a pattern shape shifted inward or outward with respect to the shape of the corner portion at a position corresponding to the corner portion of the electrode, if the shift is set to reduce the pattern formation error at the time of patterning, It is possible to suppress the occurrence of a defective display portion due to a pattern formation error in a corner portion of the electrode, and it is possible to reduce the occurrence of display defects and display defects.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a planar structure of a portion facing an electrode pattern in a liquid crystal device according to an embodiment of the present invention.

FIGS. 2A and 2B are an enlarged partial plan view showing a shape of an exposure mask in the same embodiment and an enlarged partial plan view showing a detailed shape of a resist pattern; FIGS.

FIGS. 3A, 3B and 3C are explanatory diagrams illustrating a modification of the mask shape according to the embodiment. FIGS.

FIG. 4 is a schematic plan perspective view showing the entire structure of a divided matrix type liquid crystal device.

FIG. 5 is a schematic plan view showing a structure of a portion facing an electrode pattern in a conventional divided matrix type liquid crystal device.

FIGS. 6A to 6C are process explanatory views showing a patterning method of an electrode pattern in a conventional liquid crystal device.

[Explanation of symbols]

 A, B: Pixel region E: Display drive region F: Edge facing region (facing portion) 11: Transparent substrate 11a: Segment electrode 11b: Segment electrode 11s, 11t: Overhang region 12: Transparent substrate 12a: Common electrode 12s ... Overhanging region 13 Sealing material 17 Transparent conductive film 18, 28 Photosensitive resist layer 18a, 28a Resist pattern 19, 29 Light-shielding mask 29a Opening 31a Projecting portion 32a Projecting portion 33a Projecting portion

Claims (6)

[Claims] 1. An electrode pattern forming mask used for forming a first electrode and a second electrode that are not connected to each other on a substrate so that ends of the electrodes face each other, wherein the first electrode Alternatively, the second electrode has a corner formed at a portion facing the second electrode, and the electrode pattern forming mask has a pattern shape shifted inward or outward with respect to the shape of the corner at a position corresponding to the corner. A mask for forming an electrode pattern, comprising: 2. An electrode pattern forming mask used for forming a first electrode and a second electrode, which are not connected to each other, on a substrate such that ends of the electrodes face each other. Alternatively, the second electrode is formed by etching, and the first electrode or the second electrode has a corner formed at a portion facing the corner, and the electrode pattern forming mask is formed at a position corresponding to the corner. An electrode pattern forming mask having a pattern shape projecting outward with respect to the shape of the corner portion. 3. The electrode pattern forming mask according to claim 1, wherein at a position corresponding to the corner portion, a mask shape having a largest deviation from the shape of the corner portion is provided. An electrode pattern forming mask, characterized in that: 4. The protruding contour portion according to claim 3, wherein the electrode pattern forming mask protrudes from a position corresponding to the corner portion in an extending direction or a width direction of the electrode at a position corresponding to the corner portion. A mask for forming an electrode pattern, comprising: 5. The method according to claim 1, wherein:
In the paragraph, the first electrode or the second electrode forms a photosensitive resist film on an electrode layer formed on the substrate using a constituent material of the electrode, and exposes and develops the photosensitive resist film. Forming the first or second electrode by forming a resist pattern by etching the electrode layer using the resist pattern, and being a mask for exposure of the photosensitive resist film. Characteristic mask for forming an electrode pattern. 6. A method of manufacturing an electro-optical device, wherein an electrode for applying a voltage to an electro-optical material is formed on a substrate, wherein a step of forming an electrode layer on the substrate using the constituent material of the electrode; Forming a photosensitive resist film on the electrode layer, exposing and developing the photosensitive resist film to form a resist pattern, and etching using the resist pattern, the first not connected to the substrate on the substrate Forming an electrode and a second electrode such that the ends of the electrodes face each other, wherein the first electrode or the second electrode has a corner formed at the facing portion. An exposure mask having a pattern shape shifted inward or outward with respect to the shape of the corner portion at a position corresponding to the corner portion for the exposure. Method.