JP3239632B2 - Color matrix display panel and manufacturing method thereof - Google Patents

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 method of manufacturing the same. More specifically, the present invention relates to an alignment technique for a color filter formed on one substrate and a black matrix formed on the other substrate.

[0002]

2. Description of the Related Art The general structure of a conventional color matrix display panel will be briefly described with reference to FIG. As shown, the color matrix display panel has a main substrate 101 and a sub-substrate 102 bonded to each other with a gap therebetween, and a liquid crystal 103 held in the gap. The main substrate 101 includes pixel electrodes 104 arranged in a matrix and a thin film transistor 105 for driving each pixel electrode 104.
Further, it has a gate wiring 106 and a data wiring 107 which cross in a matrix. A pixel electrode 104 and a thin film transistor 105 are arranged at each intersection of the gate wiring 106 and the data wiring 107. Each thin film transistor 105
Are connected to the corresponding gate wiring 106,
The source electrode is connected to the corresponding data line 107, and the drain electrode is connected to the corresponding pixel electrode 104. Further, although not shown, a black matrix composed of a light shielding film patterned so as to surround each pixel electrode 104 is formed on the surface of the main substrate 101.
Unnecessary parts other than 4 are shielded from 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 the respective pixel electrodes 104.
08 and a counter electrode 109. A color matrix display panel having such a configuration is connected to two polarizing plates 1.
A desired full-color image display can be obtained by sandwiching the white light between 10, 111 and white light.

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

[0004]

In order to obtain the best color resolution, the color filter 108 and the black matrix 112 need to be precisely aligned with each other. For this purpose, an alignment mark 113 is provided around the main substrate 101. The alignment mark 113 is made of, for example, a light shielding film formed at the same time as 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 bonding 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 provided on the sub-substrate side are formed by different materials and different processes, and a positional displacement always occurs between the two. Even if the 113 and 114 are perfectly matched, the black matrix 112 and the color filter
There is a problem in that an error occurs between them and the overlay accuracy is degraded. When the color filters 108 are formed, three primary color films R, G, and B are sequentially formed and are sequentially patterned so as to correspond to individual pixel electrodes.
For example, a first three primary color film R is formed and then patterned, then a three primary color film G is formed and then patterned, and finally a three primary color film B is formed and patterned. Accordingly, there is a relative displacement between the three primary color films R, G, and B. For this reason, even if the alignment mark 114 is formed using the same film as one of the three primary color films R, G, and B, a positional deviation ± Δx occurs between the remaining three primary color films.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to improve the alignment accuracy between a black matrix formed on a main substrate and a color filter formed on a sub-substrate. And The following measures were taken to achieve this purpose. That is, the color matrix display panel according to the present invention has, as a basic configuration, a main substrate and a sub-substrate joined to each other with a gap therebetween, and the electro-optical material held in the gap. The main substrate has pixel electrodes arranged in a matrix, switching elements for driving each pixel electrode, and a black matrix made of a light-shielding film patterned so as to surround the pixel electrodes.
On the other hand, the sub-substrate has a color filter composed of a three primary color film patterned for each pixel electrode, and a counter electrode. As a characteristic feature of the present invention, one alignment mark formed by laminating three primary color films patterned on the periphery of the sub-substrate is formed, and the other alignment mark patterned with a light-shielding film is formed on the periphery of the main substrate. It is formed so as to be aligned with one of the alignment marks. Note that, for example, a liquid crystal can be used as the electro-optical material.

A color matrix display panel according to the present invention is manufactured by the following steps. That is, first, a switching element and a matrix-shaped pixel electrode connected to the switching element are formed on the main substrate. Next, before or after the formation of the pixel electrode, a light-shielding film is formed and patterned to form a black matrix so as to overlap with the periphery of the pixel electrode, and at the same time, one alignment mark is formed with the same light-shielding film. In addition, three primary color films are sequentially formed on the sub-substrate, and are sequentially patterned so as to correspond to the individual pixel electrodes to form a color filter. 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 face each other with a predetermined gap therebetween, and the two substrates are joined in a state where the black matrix and the color filter are aligned with each other with reference to both alignment marks. Finally, an electro-optical material such as a liquid crystal is sealed in the gap to complete a color matrix display panel.

[0007]

According to the present invention, a light-shielding film is formed on a main substrate and patterned to form a 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 are sequentially patterned so as to correspond to individual pixel electrodes to form a color filter. At the same time, the other alignment mark is provided in a state where the three primary color films are overlapped. The two substrates are joined in a state where the black matrix and the color filter are aligned with each other with reference to the pair of alignment marks. Since alignment is performed directly using one alignment mark provided integrally with the black matrix and the other alignment mark provided integrally with the color filter, an improvement in overlay accuracy can be realized. In particular, since a portion where the three primary color films R, G, and B are stacked is used as an alignment mark, it is possible to perform optimized positioning for each color of the three primary color films. In addition, since alignment marks for positioning are created at the same time as the color filters, there is no need to provide a step for creating the alignment marks, and rationalization can be realized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing the configuration 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 joined to each other via a gap, and an electro-optical material such as a liquid crystal 3 held in the gap. Pixel electrodes 4 arranged in a matrix on the inner surface of 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 for connecting the thin film transistor 5 to the pixel electrode 4 and a wiring for connecting the thin film transistors 5 are also integrally formed. Further, as the switching element, an 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 patterned so as to surround the individual pixel electrodes 4 is formed. As the light-shielding film of the black matrix 6, for example, metal aluminum or the like can be used similarly to the wiring.
As shown in the figure, the black matrix 6 is provided in alignment with the boundaries of the individual pixel electrodes 4 and shields unnecessary portions (for example, thin film transistors 5 and wirings) other than the pixel electrodes 4 that contribute to display from incident light. It is closed. In the present embodiment, a thin film transistor 5 and a wiring are integratedly formed in a lower layer region, and an interlayer insulating film 7 covers the thin film transistor 5 and the wiring. A black matrix 6 is formed thereon by patterning 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.
The pixel electrode 4 is integrally formed on the flattening film 8 as an upper layer region. Therefore, the level of the pixel electrode 4 is extremely flat, which is suitable for performing an alignment process such as rubbing on the liquid crystal 3.

On the other hand, each pixel electrode 4
Three primary color films R, G, B patterned according to
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 patterning them sequentially so as to correspond to the individual pixel electrodes 4. This color filter 9
For example, a printing method or photolithography can be used for film formation. 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 a portion where both face the pixel electrode 4 made of TO and overlap with each other. One of the three primary color films R, G, and 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 by taking out this as a change in transmittance, a desired full-color image display can be obtained.

As a characteristic feature of the present invention, one alignment mark 12 in which three primary color films R, G, and B are laminated is formed around the sub-substrate 2.
In this embodiment, a pair of alignment marks 12 are provided on both sides of the sub-substrate 2, but the number 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, the other alignment mark 13 formed by patterning the light-shielding film around the main substrate 1 is formed so as to be aligned with the one alignment mark 12. The alignment marks 13 are provided with the same light-shielding film at the same time when the black matrix 6 is formed. For example, the alignment marks 13 on the main substrate 1 are patterned in a frame shape, and the alignment marks 12 provided on the sub-substrate 2 are patterned in a rectangular shape. The relative positions of the two substrates 1 and 2 are adjusted so that the rectangle of the alignment mark 12 fits within the frame of the alignment mark 13 and the black matrix 6 and the color filter 9 are aligned.

FIG. 2 is a schematic plan view showing an example of an alignment mark 12 in which 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.
It is only shifted. The rectangular pattern of the blue film B is shifted downward and rightward by Δx with respect to the rectangular pattern of the green film G. As described above, the three primary color films R, G, and B generally may be relatively shifted by Δx at most in various directions. This is because color filters and alignment marks are formed by sequentially patterning the three primary color films R, G, and B. In the case of (A), three primary color films R,
The black portion where G and B overlap becomes the effective alignment mark 12. Assuming that the true center of the sub-substrate matches the center of the rectangular pattern of the green film G, the center of the alignment mark 12 matches the true center (represented by a + sign). 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, so that high-precision alignment can be performed. Is possible.

In the example shown in FIG. 2B, the red film R is shifted upward and rightward by Δx with respect to the green film G. On the other hand, the blue film B is shifted downward and rightward by Δx with respect to the green film G. In this case, the three primary color films R,
The center (indicated by a black circle, the same applies hereinafter) of the alignment mark 12 defined in the black portion where G and B overlap each other is shifted by Δx / 2 from the true center (indicated by the positive sign, same applies hereinafter). become. Therefore, the alignment error is Δx /
2, which is half that of the prior art.

In the example of (C), the red film R is shifted to the left relative to the green film G by Δx. The blue film B is shifted downward and rightward by Δx relative to the green film G. In this case, the center of the alignment mark 12 composed of the overlapping black portions of the three primary color films R, G, and B is also shifted by Δx / 2 from the true center.

In the example (D), the red film R is shifted upward by Δx relative to the green film G.
The blue film B is shifted downward and rightward by Δx relative to the green film G. Three primary color film R,
The center of the alignment mark 12 defined in the overlapping portion of G and B is shifted from the true center by Δx / 2.

In the example of (E), the red film R is shifted downward and left relative to the green film G by Δx. The blue film B is shifted downward and rightward by Δx relative to the green film G. The center of the alignment mark 12 defined by the overlapping black portions of the three primary color films R, G, and B is shifted 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, and B stacked on the sub-substrate are overlapped is recognized as an alignment mark, and the center of the alignment mark and the true center are recognized. As shown in (A) to (E), the maximum deviation is Δx / 2 at the maximum, and the positional accuracy is improved by about 50% with respect to the conventional deviation Δx.

Finally, referring to the flowchart of FIG.
A method for manufacturing the color matrix display panel shown in FIG. 1 will be described in detail. First, the steps on the sub-substrate 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, an alignment mark is formed with the three primary color films overlapping. Next, in step S2, a counter electrode is formed after forming a flattening film on the color filter. Next, after cleaning the substrate in step S3, the surface of the counter electrode is coated with an alignment film in step S4.
In step S5, a rubbing treatment is performed on the surface of the alignment film.

Next, in the processing step on the main substrate side, first, in step S6, a thin film transistor, a wiring, 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 this time, an alignment mark is also formed simultaneously with the same light-shielding film. Next, in step S8, after the black matrix is covered with the flattening film, a pixel electrode is formed thereon. Subsequently, after cleaning the substrate in step S9, the alignment film is coated in step S10. Thereafter, a rubbing treatment of the alignment film is performed in step S11, and further, a seal printing is performed in step S12.

After processing the sub-substrate and the main substrate in this manner, in step S13, the two substrates face each other with a predetermined gap therebetween, and the black matrix and the color filter are aligned with each other with reference to both alignment marks. The two substrates are joined. Subsequently, in step S14, the sub-substrate and the main substrate bonded to each other are divided and separated 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 subjected to a heat treatment to stabilize the alignment state. Thus, a 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 simultaneously with the color filter. On the periphery of the main substrate, another alignment mark formed by patterning a light shielding film is formed simultaneously with 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 achieve an effect of realizing a high aperture ratio and a high definition of the color matrix display panel. There is.
Further, since the number of steps for forming the alignment marks on the sub-substrate side can be reduced, the cost of the color matrix display panel can be reduced. From the above, the effect is obtained that a color matrix display panel with high transmittance, high pixel density and high display quality can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic 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 simultaneously with a color filter.

FIG. 3 is a flowchart showing a manufacturing process 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 cross-sectional view showing a configuration of an alignment mark of a conventional color matrix display panel.

[Explanation of symbols]

 DESCRIPTION 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1335 505 G02F 1/1368

Claims (3)

(57) [Claims] 1. A semiconductor device comprising: a main substrate and a sub-substrate joined to each other via a gap; and an electro-optical material held in the gap. The main substrate drives pixel electrodes arranged in a matrix and drives each pixel electrode And a black matrix composed of a light-shielding film patterned so as to surround the pixel electrode. The sub-substrate has a color filter composed of three primary color films patterned corresponding to each pixel electrode, and a counter electrode. A color matrix display panel having: a first alignment mark formed by laminating patterned three primary color films around the sub-substrate; and a light-shielding film around the main substrate. A color matrix display panel, wherein the other patterned alignment mark is formed so as to be aligned with the one alignment mark. . 2. The color matrix display panel according to claim 1, wherein said electro-optical material is a 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 or patterning a light-shielding film before or after forming the pixel electrode, and forming the pixel electrode by patterning. Forming a black matrix so as to overlap with the periphery of the same and simultaneously forming one alignment mark with the same light-shielding film, and sequentially forming three primary color films on the sub-substrate and patterning them sequentially so as to correspond to individual pixel electrodes. Forming a color filter and simultaneously forming the other alignment mark in a state where the three primary color films are overlapped; forming an opposing electrode on the color filter; and facing the main substrate and the sub-substrate via a predetermined gap. The two substrates with the black matrix and color filter aligned with each other based on both alignment marks. Process and method for producing a color matrix display panel for performing the step of encapsulating the electrooptic material in the gap to focus.