JPH0862597A - Color matrix display panel and its production - Google Patents

Abstract

PURPOSE: To improve the relative alignment accuracy of color filters formed on one substrate and a black matrix formed on the other substrate. CONSTITUTION: This color matrix display panel has the main substrate 1 and auxiliary substrate 2 joined to each other apart a spacing and liquid crystals 3 held in this spacing. The main substrate 1 has pixel electrodes 4 arranged in a matrix form, thin-film transistors 5 for driving the respective pixel electrodes 4 and the black matrix 6 which is patterned so as to enclose the pixel electrodes and consists of light shielding film. The auxiliary substrate 2 has the color filters 9 consisting of three primary color films R, G, B patterned in correspondence to the respective pixel electrodes 4 and counter electrodes 11. Alignment marks 12 on one side laminated with the patterned three primary color films R, G, B are formed on the periphery of the auxiliary substrate 2. The alignment marks 13 on the other side formed by patterning light shielding films are formed simultaneously with the black matrix 6 on the periphery of the main substrate 2. The color filters 9 and the black matrix 6 are aligned by matching both alignment marks 12, 13 to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color matrix display panel and a manufacturing method thereof. More specifically, it relates to an alignment technique of a color filter formed on one substrate and a black matrix formed on the other substrate.

[0002]

2. Description of the Related Art A general structure of a conventional color matrix display panel will be briefly described with reference to FIG. As shown in the figure, the color matrix display panel has a main substrate 101 and a sub-substrate 102, which are bonded to each other through a gap, and a liquid crystal 103 held in the gap. The main substrate 101 has pixel electrodes 104 arranged in a matrix and thin film transistors 105 that drive each pixel electrode 104.
Further, it has gate wirings 106 and data wirings 107 that intersect in a matrix. The pixel electrode 104 and the thin film transistor 105 are arranged at each intersection of the gate line 106 and the data line 107. Each thin film transistor 105
The gate electrode of is connected to the corresponding gate wiring 106,
The source electrode is connected to the corresponding data wiring 107, and the drain electrode is connected to the corresponding pixel electrode 104. Further, although not shown, a black matrix made of a light shielding film which is patterned so as to surround each pixel electrode 104 is formed on the surface of the main substrate 101.
The unnecessary parts other than 4 are shielded from the incident light. On the other hand, the sub-substrate 102 is a color filter 1 composed of three primary color films R, G, B patterned corresponding to each pixel electrode 104.
08 and a counter electrode 109. A color matrix display panel having such a structure is provided with two polarizing plates 1
When sandwiched between 10 and 111 and white light is made incident, a desired full-color image display can be obtained.

FIG. 5 is a partial sectional view showing a main part of the conventional color matrix display panel shown in FIG. Innumerable pixel electrodes 104 are formed on the lower main substrate 101. The black matrix 112 is patterned along the boundary of each pixel electrode 104 to perform optical pixel separation. By providing the black matrix 112, the contrast of the image can be improved. On the other hand, on the upper sub-substrate 102, a color filter 108 composed of three primary color films R, G, B patterned corresponding to each pixel electrode 104 and a counter electrode 109 are formed.

[0004]

In order to obtain the best color resolution, the color filter 108 and the black matrix 112 must be precisely aligned with each other. For this purpose, alignment marks 113 are provided around the main substrate 101. The alignment mark 113 is made of, for example, a light-shielding film formed simultaneously with the patterning of the black matrix 112. Corresponding alignment marks 114 are also formed around the sub-substrate 102. When assembling the color matrix display panel by joining the two substrates 101 and 102 to each other, the black matrix 112 and the color filter 108 are relatively aligned by aligning the pair of alignment marks 113 and 114 with each other. However, in the conventional structure, the color filter 108 and the alignment mark 114, which are provided on the sub-substrate side, are formed of different materials and in different steps, and a positional deviation always occurs between them, so even if a pair of alignment marks is used. Even if 113 and 114 are perfectly aligned, the black matrix 112 and the color filter 108 are
However, there is a problem that an error occurs between the two and that the overlay accuracy is deteriorated. Further, when the color filter 108 is formed, the three primary color films R, G and B are sequentially formed and sequentially patterned so as to correspond to the individual pixel electrodes.
For example, after the first three-primary color film R is formed, this is patterned, then the three-primary color film G is formed, then this pattern is formed, and finally the three-primary color film B is formed and this pattern is formed. Therefore, a relative positional deviation also occurs between the three primary color films R, G, and B. Therefore, even if the alignment mark 114 is created using the same film as one of the three primary color films R, G, and B, a positional deviation ± Δx will occur between the remaining primary colors of the three primary color films.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, it is an object of the present invention to improve the alignment accuracy of the black matrix formed on the main substrate and the color filter formed on the sub substrate. And The following measures have been taken in order to achieve this object. That is, the color matrix display panel according to the present invention has, as a basic structure, a main substrate and a sub-substrate bonded to each other through a gap, and an electro-optical material held in the gap. The main substrate has pixel electrodes arranged in a matrix, switching elements that drive each pixel electrode, and a black matrix made of a light-shielding film that is patterned so as to surround the pixel electrodes.
On the other hand, the sub-substrate has a color filter made of a three-primary-color film patterned corresponding to each pixel electrode, and a counter electrode. As a feature of the present invention, one alignment mark formed by laminating patterned three primary color films is formed around the sub-substrate, and the other alignment mark obtained by patterning the light-shielding film is formed around the main substrate. It is formed so as to match one of the alignment marks. Liquid crystal can be used as the electro-optical material.

The color matrix display panel according to the present invention is manufactured by the following steps. That is, first, the switching elements and the matrix-shaped pixel electrodes connected to the switching elements are formed on the main substrate. Next, before or after forming the pixel electrode, a light-shielding film is formed and patterned to form a black matrix so as to overlap the periphery of the pixel electrode, and at the same time, one alignment mark is formed with the same light-shielding film. Further, three primary color films are sequentially formed on the sub-substrate, and patterning is sequentially performed so as to correspond to each pixel electrode to form a color filter, and at the same time, the other alignment mark is formed in a state where the three primary color films are overlapped. Subsequently, a counter electrode is formed on the color filter. After this,
The main substrate and the sub-substrate are opposed to each other with a predetermined gap therebetween, and the two substrates are bonded together with the black matrix and the color filter aligned with each other with reference to the alignment marks of both. Finally, an electro-optical material such as liquid crystal is filled in the gap to complete a color matrix display panel.

[0007]

According to the present invention, the light-shielding film is formed on the main substrate and patterned to form the black matrix so as to overlap the periphery of each pixel electrode. At the same time, one alignment mark is provided with the same light-shielding film.
In addition, three primary color films are sequentially formed on the sub-substrate, and patterning is sequentially performed so as to correspond to each pixel electrode to form a color filter. At the same time, the other alignment mark is provided with the three primary color films overlapping. The two substrates are bonded together while the black matrix and the color filter are aligned with each other based on the pair of alignment marks. Since one alignment mark provided integrally with the black matrix and the other alignment mark provided integrally with the color filter are used for direct alignment, the overlay accuracy can be improved. In particular, since the portion where the three primary color films R, G, and B are laminated is used as an alignment mark, it is possible to perform the optimized alignment for each color of the three primary color films. Further, since the alignment mark for positioning is created at the same time as the color filter, there is no need to provide a process for creating the alignment mark, and rationalization can be realized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic sectional view showing the structure of a color matrix display panel according to the present invention. As shown in the figure, the present color matrix display panel has a main substrate 1 and a sub-substrate 2 which are bonded to each other through a gap, and an electro-optical substance such as a liquid crystal 3 held in the gap. Pixel electrodes 4 arranged in a matrix on the inner surface of the main substrate 1.
And a switching element such as a thin film transistor 5 for driving each pixel electrode 4 are integrally formed. Although not shown, a wiring that connects the thin film transistor 5 and the pixel electrode 4, a wiring that connects the thin film transistors 5 to each other, and the like are also integrally formed. Further, as the switching element, MIM or the like can be used instead of the thin film transistor (TFT) 5. Further, a black matrix 6 made of a light shielding film which is patterned so as to surround each pixel electrode 4 is formed. As the light-shielding film of the black matrix 6, for example, metal aluminum or the like can be used as in the case of wiring.
As shown in the figure, the black matrix 6 is provided so as to be aligned with the boundaries of the individual pixel electrodes 4 and also shields unnecessary portions other than the pixel electrodes 4 that contribute to display (for example, thin film transistors 5 and wiring) from incident light. It's closed. In this embodiment, the thin film transistor 5 and the wiring are integratedly formed in the lower layer region, and the interlayer insulating film 7 covers the upper portion thereof. A black matrix 6 is formed as a pattern on the black matrix 6 as an intermediate region. A flattening film 8 is formed so as to cover the black matrix 6. The flattening film 8 is made of, for example, a transparent polymer film and fills the surface irregularities of the main substrate 1.
Pixel electrodes 4 are integratedly formed as an upper layer region on the flattening film 8. Therefore, the level of the pixel electrode 4 is extremely flat, which is suitable for performing alignment treatment such as rubbing on the liquid crystal 3.

On the other hand, each pixel electrode 4 is formed on the inner surface of the sub-substrate 2.
The three primary color films R, G, B patterned in accordance with
A color filter 9 is formed. The color filter 9 is formed by sequentially forming three primary color films R, G and B on the sub-substrate 2 and sequentially patterning them so as to correspond to the individual pixel electrodes 4. This color filter 9
For the film formation of, for example, a printing method or photolithography can be used. A counter electrode 11 is formed on the color filter 9 via a flattening film 10. The counter electrode 11 is made of a transparent conductive film such as ITO,
Each pixel is defined in the overlapping portion of the two facing the pixel electrode 4 made of TO. One of the three primary color films R, G, B is assigned to each pixel. By applying a voltage between the pixel electrode 4 and the counter electrode 11, the alignment state of the liquid crystal 3 changes, and the desired full-color image display can be obtained by extracting this as a change in transmittance.

As a feature of the present invention, one alignment mark 12 formed by laminating the patterned three primary color films R, G, B is formed around the sub-substrate 2.
Although a pair of alignment marks 12 are provided on both sides of the sub-substrate 2 in this embodiment, the number thereof is not limited to this. The alignment mark 12 is provided at the same time when the color filter 9 is formed, and the black portion where the three primary color films R, G, and B overlap is an effective alignment mark. On the other hand, around the main substrate 1, the other alignment mark 13 obtained by patterning the light shielding film is formed so as to be aligned with the one alignment mark 12. The alignment mark 13 is provided on the same light-shielding film as the black matrix 6 is formed. For example, the alignment mark 13 on the main substrate 1 side is patterned in a frame shape, and the alignment mark 12 provided on the sub substrate 2 is patterned in a rectangular shape. The black matrix 6 and the color filter 9 are aligned by adjusting the relative positions of the substrates 1 and 2 so that the rectangle of the alignment mark 12 fits within the frame of the alignment mark 13.

FIG. 2 is a schematic plan view showing an example of the alignment mark 12 in which the three primary color films R, G and B are laminated. In the example of (A), the rectangular pattern of the red film R is Δx upward and leftward with respect to the rectangular pattern of the green film G.
Just shifted. The rectangular pattern of the blue film B is shifted from the rectangular pattern of the green film G by Δx downward and rightward. Thus, the three primary color films R, G, B can generally be displaced by a maximum of Δx in various directions. This is because the three primary color films R, G and B are sequentially patterned to form a color filter and an alignment mark. In the case of (A), the three primary color films R,
The black portion where G and B overlap is the effective alignment mark 12. If the true center of the sub-substrate coincides with the center of the rectangular pattern of the green film G, the center of the alignment mark 12 coincides with the true center (denoted by + mark). In other words, even if the red film R and the blue film B are shifted relative to the green film G, the center of the alignment mark 12 coincides with the true center of the sub-substrate, and high-precision alignment should be performed. Is possible.

In the example of (B), the red film R is shifted upward and rightward from the green film G by Δx. On the other hand, the blue film B is displaced from the green film G by Δx downward and rightward. In this case, the three primary color films R,
The center of the alignment mark 12 (represented by a black circle, the same applies to the following) defined by the overlapping black portions of G and B is offset by Δx / 2 minutes from the true center (represented by a + sign and applies to the following). become. Therefore, the alignment error is Δx /
It is 2 and can be halved compared to the conventional one.

In the example of (C), the red film R is displaced leftward relative to the green film G by Δx. Further, the blue film B is relatively shifted from the green film G downward and to the right by Δx. In this case, the center of the alignment mark 12 formed of the black portions where the three primary color films R, G, and B are overlapped is still deviated from the true center by Δx / 2.

In the example of (D), the red film R is relatively upwardly displaced from the green film G by Δx.
Further, the blue film B is displaced from the green film G by Δx downward and to the right. Three primary color film R,
The center of the alignment mark 12 defined in the overlapping portion of G and B is deviated from the true center by Δx / 2.

In the example of (E), the red film R is displaced downward and to the left relative to the green film G by Δx. Further, the blue film B is displaced from the green film G by Δx downward and to the right. The center of the alignment mark 12 defined by the overlapping black portions of the three primary color films R, G, and B is displaced from the true center by Δx / 2.

As described above, in the present invention, the black portion where the three primary color films R, G, B laminated on the sub-substrate are image-recognized as an alignment mark, so that the center of the alignment mark and the true center are formed. As shown in the cases (A) to (E), the maximum deviation is Δx / 2, and the positional accuracy is improved by about 50% with respect to the conventional deviation amount Δx.

Finally, referring to the flowchart of FIG.
A method of manufacturing the color matrix display panel shown in FIG. 1 will be described in detail. First, the process on the sub-board side will be described. First, in step S1, three primary color films are sequentially formed on the surface of the sub substrate and patterned to form a color filter. At the same time, alignment marks are also formed with the three primary color films overlapping. Next, in step S2, a flattening film is formed on the color filter and then a counter electrode is formed. Next, after cleaning the substrate in step S3, the surface of the counter electrode is coated with an alignment film in step S4.
Further, in step S5, the surface of the alignment film is rubbed.

Next, in the processing step on the main substrate side, first, in step S6, thin film transistors, wirings and the like are integrated and formed. Next, in step S7, a light-shielding film is formed and patterned to form a black matrix. At the same time, alignment marks are also formed with the same light-shielding film. Next, in step S8, the black matrix is covered with a flattening film, and then a pixel electrode is formed thereon. Subsequently, after cleaning the substrate in step S9, the alignment film is coated in step S10. After that, the alignment film is rubbed in step S11, and the sticker printing is performed in step S12.

After the sub-substrate and the main substrate are processed in this way, both substrates are opposed to each other through a predetermined gap in step S13, and the black matrix and the color filter are aligned with each other with reference to both alignment marks. Join both substrates. Subsequently, in step S14, the sub-substrate and the main substrate bonded to each other are divided into individual liquid crystal display panels. After the separation, in step S15, liquid crystal is injected into each panel and then sealed. Finally step S1
In step 6, the liquid crystal is heat-treated to stabilize the alignment state. In this way, the color matrix display panel is completed.

[0020]

As described above, according to the present invention, one alignment mark formed by laminating patterned three primary color films is formed around the sub-substrate at the same time as the color filter. Further, the other alignment mark obtained by patterning the light shielding film is formed around the main substrate at the same time as the black matrix. The color filter and the black matrix are aligned by aligning the pair of alignment marks with each other. With such a configuration, it is possible to improve the overlay accuracy of the color filter formed on the sub substrate and the black matrix formed on the main substrate, and it is possible to realize a high aperture ratio and high definition of the color matrix display panel. There is.
Further, since the step of forming the alignment mark on the sub substrate side can be omitted, there is an effect that the cost of the color matrix display panel is reduced. From the above, it is possible to obtain an effect that a color matrix display panel having high transmittance, high pixel density, and high display quality can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration of a color matrix display panel according to the present invention.

FIG. 2 is a schematic plan view showing a pattern of an alignment mark created at the same time as a color filter.

FIG. 3 is a flowchart showing manufacturing steps of the color matrix display panel shown in FIG.

FIG. 4 is a schematic perspective view showing a general configuration of a conventional color matrix display panel.

FIG. 5 is a schematic partial sectional view showing an alignment mark configuration of a conventional color matrix display panel.

[Explanation of symbols]

 1 Main Substrate 2 Sub Substrate 3 Liquid Crystal 4 Pixel Electrode 5 Thin Film Transistor 6 Black Matrix 7 Interlayer Insulating Film 8 Flattening Film 9 Color Filter 10 Flattening Film 11 Counter Electrode 12 Alignment Mark 13 Alignment Mark

Claims (3)

[Claims] 1. A main substrate and a sub-substrate bonded to each other through a gap, and an electro-optical material held in the gap, the main substrate driving pixel electrodes arranged in a matrix and driving each pixel electrode. Switching element and a black matrix made of a light shielding film that is patterned so as to surround the pixel electrode, the sub-substrate is a color filter made of a three-primary-color film that is patterned corresponding to each pixel electrode, and a counter electrode. A color matrix display panel having: an alignment mark formed by laminating patterned three primary color films is formed around the sub-substrate, and a light-shielding film is formed around the main substrate. A color matrix display panel characterized in that the other patterned alignment mark is formed to match the one alignment mark. . 2. The color matrix display panel according to claim 1, wherein the electro-optical material is liquid crystal. 3. A step of forming a switching element and a matrix-shaped pixel electrode connected to the switching element on a main substrate, and forming a light-shielding film before or after forming the pixel electrode and patterning the pixel electrode. The process of forming a black matrix so that it overlaps with the periphery of the same, and at the same time forming one alignment mark with the same light-shielding film, and sequentially forming three primary color films on the sub-substrate and patterning them in order to correspond to individual pixel electrodes. Forming the other alignment mark at the same time as forming the color filters while the three primary color films are superposed, forming a counter electrode on the color filter, and facing the main substrate and the sub substrate with a predetermined gap therebetween. Then, with the black matrix and the color filter aligned with each other based on both alignment marks, both substrates are Process and method for producing a color matrix display panel for performing the step of encapsulating the electrooptic material in the gap to focus.