Color filter and manufacturing method thereof

The present invention provides a color filter and a manufacturing method thereof. The method includes steps of: coating a first material layer on a substrate and patterning it to have first photoresists, first filter portions and first spacer portions; coating a second material layer on the substrate and patterning it to have second photoresists, second filter portions and second spacer portions; and coating a third material layer on the substrate and patterning it to have third photoresists, third filter portions and third spacer portions; and the first, the second, the third filter portions are correspondingly overlapped with each other, and the first, the second, the third spacer portions are correspondingly overlapped with each other.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a field of liquid crystal display technology, especially to a color filter and a manufacturing method thereof.

2. Description of the Related Art

Generally, a conventional manufacturing process of color filter of liquid crystal display device firstly mounts a black matrix layer on a substrate, then respectively disposes photo-resist layers of different colors (red, green and blue) on the substrate, and lastly mounts photo spacers on the substrate so as to control the cell gap of a liquid crystal cell.

In the above-mentioned manufacturing process, the black matrix layer, the red, green, blue photo-resist layers and the photo spacers are respectively formed through a photolithography process including coating, exposure and development steps. Therefore, the process of manufacturing a color filter needs to repeat the photolithography process at least five times, which not only results in a waste of material, but also extends the cycle time of the manufacturing process and thereby raising process cost.

SUMMARY OF THE INVENTION

An objective of the invention is to provide a manufacturing method of color filter to solve the technical problem of high process cost and long process time caused by the conventional technology that requires a photolithography process for making black matrix layer and another photolithography process for making photo spacers.

In order to solve the technical problem, the present invention provides a manufacturing method of color filter, and the manufacturing comprises steps of:

providing a substrate;

coating a first material layer on the substrate;

performing photolithography to the first material layer through a specific mask so as to pattern the first material layer to have multiple first photoresists and multiple first filter portions, wherein each of the first photoresists is connected to one of the first filter portions, and each of the first filter portions includes a first spacer portion formed on and protruding from a top surface of the first filter portion;

continuing to coat a second material layer on the substrate;

performing photolithography to the second material layer through the specific mask so as to pattern the second material layer to have multiple second photoresists alternately arranged with the first photoresists side by side at intervals and have multiple second filter portions overlapped with the first filter portions, wherein each of the second filter portions includes a second spacer portion formed on and protruding from a top surface of the second filter portion, and the second spacer portions correspond in position to the first spacer portions, respectively;

continuing to coat a third material layer; and

performing photolithography to the third material layer through the specific mask to pattern the third material layer to have multiple third photoresists alternately arranged with the first photoresists and the second photoresists side by side at intervals and have multiple third filter portions overlapped with the second filter portions, wherein each of the third filter portions includes a third spacer portion formed on and protruding from a top surface of the third filter portion, and the third spacer portions correspond in position to the second spacer portions, respectively; wherein

the specific mask includes multiple transparent areas for forming the first, the second and the third photoresists, multiple first half-transparent areas for forming the first, the second and the third filter portions and multiple shielding areas that are alternately arranged with the transparent areas; and

each of the first half-transparent areas further has a second half-transparent area for forming the first, the second and the third spacer portions.

In one embodiment of the manufacturing method of color filter of the present invention, each of the second photoresists is connected to a corresponding one of the second filter portions.

In one embodiment of the manufacturing method of color filter of the present invention, each of the third photoresists is connected to a corresponding one of the third filter portions.

In one embodiment of the manufacturing method of color filter of the present invention, the method further includes steps of:

continuing to coat a fourth material layer on the substrate; and

perform photolithography to fourth material layer through the specific mask so as to pattern the fourth material layer to have multiple fourth photoresists alternately arranged with the first, the second and the third photoresists side by side at intervals and have multiple fourth filter portions overlapped with the third filter portions, wherein each of the fourth filter portions further includes a fourth spacer portion formed on and protruding from a top surface of the fourth filter portion, and the fourth spacer portions correspond in position to the third spacer portions, respectively.

In one embodiment of the manufacturing method of color filter of the present invention, each of the fourth photoresists is connected to a corresponding one of the fourth filter portions.

Another objective of the present invention is to provide a manufacturing method of color filter to solve the technical problem of high process cost and long process time caused by the conventional technology requiring a photolithography process for making black matrix layer and another photolithography process for making photo spacers.

In order to solve the aforementioned technical problem, the present invention provides a manufacturing method of color filter, and the manufacturing comprises steps of:

providing a substrate;

coating a first material layer on the substrate;

performing photolithography to the first material layer through a specific mask so as to pattern the first material layer to have multiple first photoresists and multiple first filter portions, wherein each of the first photoresists is connected to one of the first filter portions, and each of the first filter portions includes a first spacer portion formed on and protruding from a top surface of the first filter portion;

continuing to coat a second material layer on the substrate;

performing photolithography to the second material layer through the specific mask so as to pattern the second material layer to have multiple second photoresists alternately arranged with the first photoresists side by side at intervals and have multiple second filter portions overlapped with the first filter portions, wherein each of the second filter portions includes a second spacer portion formed on and protruding from a top surface of the second filter portion, and the second spacer portions correspond in position to the first spacer portions, respectively;

continuing to coat a third material layer; and

performing photolithography to the third material layer through the specific mask to pattern the third material layer to have multiple third photoresists alternately arranged with the first photoresists and the second photoresists side by side at intervals and have multiple third filter portions overlapped with the second filter portions, wherein each of the third filter portions includes a third spacer portion formed on and protruding from a top surface of the third filter portion, and the third spacer portions correspond in position to the second spacer portions, respectively.

In one embodiment of the manufacturing method of color filter of the present invention, each of the first photoresists is connected to a corresponding one of the first filter portions; each of the second photoresists is connected to a corresponding one of the second filter portions; and each of the third photoresists is connected to a corresponding one of the third filter portions.

In one embodiment of the manufacturing method of color filter of the present invention, the specific mask includes multiple transparent areas for forming the first, the second and the third photoresists, multiple first half-transparent areas for forming the first, the second and the third filter portions and multiple shielding areas that are alternately arranged with the transparent areas; and

each of the first half-transparent areas further has a second half-transparent area for forming the first, the second and the third spacer portions.

In one embodiment of the manufacturing method of color filter of the present invention, the method further includes steps of:

continuing to coat a fourth material layer on the substrate; and

perform photolithography to fourth material layer through the specific mask so as to pattern the fourth material layer to have multiple fourth photoresists alternately arranged with the first, the second and the third photoresists side by side at intervals and have multiple fourth filter portions overlapped with the third filter portions, wherein each of the fourth filter portions further includes a fourth spacer portion formed on and protruding from a top surface of the fourth filter portion, and the fourth spacer portions correspond in position to the third spacer portions, respectively.

In one embodiment of the manufacturing method of color filter of the present invention, each of the fourth photoresists is connected to a corresponding one of the fourth filter portions.

Still another objective of the present invention is to provide a color filter to solve the technical problem of high process cost and long process time caused by the conventional technology requiring a photolithography process for making black matrix layer and another photolithography process for making photo spacers.

In order to solve the technical problem, the present invention provides a color filter comprising multiple first photoresists, multiple second photoresists and multiple third photoresists alternately arranged with each other side by side at intervals on a substrate; wherein the first, the second and the third photoresists further have multiple first filter portions, second filter portions and third filter portions mounted therebetween, wherein each of the first filter portions is overlapped with a corresponding one of the second filter portions and a corresponding one of the third filter portions; each of the first filter portions includes a first spacer portion formed on and protruding from a top surface of the first filter portion; each of the second filter portions includes a second spacer portion formed on and protruding from a top surface of the second filter portion; each of the third filter portions includes a third spacer portion formed on and protruding from a top surface of the third filter portion; wherein

the first spacer portions, the first filter portions and the first photoresists are formed together by performing photolithography to a first material layer on the substrate; the second spacer portions, the second filter portions and the second photoresists are formed together by performing photolithography to a second material layer on the substrate; and the third spacer portions, the third filter portions and the third photoresists are formed together by performing photolithography to a third material layer on the substrate.

In one embodiment of the color filter of the present invention, each of the first photoresists is connected to a corresponding one of the first filter portions; each of the second photoreisits is connected to a corresponding one of the second filter portions; and each of the third photoreisits is connected to a corresponding one of the third filter portions.

In one embodiment of the color filter of the present invention, the total thickness of the overlapped first, the second and the third spacer portions on the substrate is relatively larger than the thickness of the first photoresist, the thickness of the second photoresist or the thickness of the third photoresist on the substrate.

In one embodiment of the color filter of the present invention, the color filter further includes multiple fourth photoresists, multiple fourth filter portions and multiple fourth spacer portions, wherein the fourth photoresists are arranged alternately with the first, the second and the third photoresists side by side at intervals on the substrate; and

each of the fourth filter portions is overlapped with a corresponding one of the first filter portions, a corresponding one of the second filter portions and a corresponding one of the third filter portions; each of the fourth spacer portions is formed on and protrudes from a top surface of a corresponding one of the fourth filter portions and corresponds to a corresponding one of the third spacer portions; the fourth spacer portions, the fourth filter portions and the fourth photoresists are formed together by performing photolithography to a fourth material layer on the substrate.

In one embodiment of the color filter of the present invention, each of the fourth photoresists is connected to a corresponding one of the fourth filter portions.

The present invention uses the material layers that are used for manufacturing red, green and blue photoresists to further form the overlapped first, second and third filter portions while manufacturing the red, green and blue photoresists. The first, the second and the third filter portions can respectively absorb light of different wavelengths so as to provide a light-shielding effect like black matrix, thus the overall manufacturing process does not need another specific photolithography process to manufacture a black matrix layer. Besides, in the processes of forming the first, the second and the third filter portions, the first, the second and the third spacer portions are correspondingly formed on and protruding from the top surface of the first, the second and the third filter portions so that the overall manufacturing process does not need another process to form spacers. Hence, material can be saved, production cost can be reduced, and the cycle time of the manufacturing process is shortened and thereby improving the production efficiency.

In order to make the contents of the present invention to be more easily understood, the preferred embodiments of the present invention are described in detail in cooperation with accompanying drawings as follows:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The foregoing objects, features and advantages adopted by the present invention can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings. Furthermore, the directional terms described in the present invention, such as upper, lower, front, rear, left, right, inner, outer, side and etc., are only directions referring to the accompanying drawings, so that the used directional terms are used to describe and understand the present invention, but the present invention is not limited thereto.

In the drawings, units with similar structure are labeled with the same reference number.

With reference toFIG. 1andFIGS. 2A to 2J,FIG. 1is a flow chart of a preferred embodiment of a manufacturing method of color filter in accordance with the present invention, andFIGS. 2A-2Jare schematic views illustrating the manufacturing process of color filter of the present invention.

In a step of S101, provide a substrate10and a specific mask100, and coating a first material layer20on the substrate10.

With reference to bothFIG. 2AandFIG. 2B,FIG. 2Ais a cross-sectional view of the substrate10, the first material layer100and the specific mask100, andFIG. 2Bis a top view of the specific mask100.

The mask100, in an order from large to small of degrees of transparency, has multiple transparent areas101, multiple second half-transparent areas104, multiple first half-transparent areas102and multiple shielding areas103.

With further reference toFIG. 2C, in a step of S102, perform photolithography to the first material layer20through the specific mask100so as to pattern the first material layer20to have multiple first photoresists21and multiple first filter portions22, multiple first coating areas23, multiple second coating areas24and multiple first spacer portions25(as shown inFIG. 2D), wherein the photolithography comprises steps of exposure, development and curing, andFIG. 2Cis a cross-sectional view of the substrate10and the patterned first material layer20.

With reference toFIG. 2C, a first filter portion22, a first coating area23, another first filter portion22, a second coating area24and still another first filter portion22are formed in order along a direction “A” between two adjacent first photoresists21. With further reference toFIG. 2D, each of the first filter portions22has a first spacer portion25being formed on and protruding from a top surface of each of the first filter portions22.

With further reference toFIG. 2E,FIG. 2Eis a top view ofFIG. 2C. Because the first material layer20is a layer of negative photoresist, the portion of the photoresist that is exposed to more lights becomes insoluble to the photoresist developer and is preserved during the development process. Hence, according to the specific mask100shown inFIG. 2B, the first photoresists21are formed through the transparent areas101of the specific mask100during the photolithography process; the first filter portions22are formed through the first half-transparent areas102of the specific mask100during the photolithography process; the first coating areas23and the second coating areas24are formed through the shielding areas103of the specific mask100during the photolithography process; and the first spacer portions25are formed through the second half-transparent areas104of the specific mask100during the photolithography process.

In a step of S103, continue to coat a second material layer on the substrate10, and then perform photolithography to the second material layer so as to form multiple second photoresists31on the first coating areas23, as shown inFIG. 2F, whereinFIG. 2Fis a cross-sectional view of the substrate10, the first photoresists21and the second photoresists31.

In the meantime, a few portions of the second material layer are correspondingly reserved on the first filter portions22to become multiple second filter portions32while continuing to keep the second coating areas24. In a specific implementation process, with reference toFIG. 2G, each of the second filter portions32further has a second spacer portion35formed on and protruding from a top surface of the second filter portion32, wherein the second spacer portion35corresponds to one of the first spacer portions25.

With further reference toFIG. 2G, according to the specific mask100shown inFIG. 2B, the second photoresists31are formed through the transparent areas101of the specific mask100during another photolithography process; the second filter portions32are formed through the first half-transparent areas102of the specific mask100during the photolithography process; the second coating areas24are kept through the shielding areas103of the specific mask100during the photolithography process; and the second spacer portions35are formed through the second half-transparent areas104of the specific mask100during the photolithography process. In a specific implemented operation, the specific mask100can be controlled to move along the direction “A” and cooperates with the photolithography to form the second photoresists31and the second filter portions32.

In a step of S104, continue to coat a third material layer on the substrate10, and perform photolithography to the third material layer through the specific mask100so as to form multiple third photoresists41on the second coating areas24, as shown inFIG. 2H, whereinFIG. 2His a cross-sectional view of the substrate10, the first photoresists21, the second photoresists31and the third photoresist41.

In the meantime, a few portions of the third material layer31are correspondingly reserved on the second filter portions32to become multiple third filter portions42, wherein each of the third filter portions42further has a third spacer portion (not shown in the figure, but can be referred toFIG. 2D) on a top surface of the third filter portion42.

With reference toFIG. 2I, according to the specific mask100shown inFIG. 2B, the third photoresists41are formed through the transparent areas101of the specific mask100during another photolithography process; the third filter portions42are formed through the first half-transparent areas102of the specific mask100during the photolithography process; and the third spacer portions are formed through the second half-transparent areas104of the specific mask100during the photolithography process, wherein the specific mask100can be controlled to move along the direction “A” and cooperate with the photolithography process to form the foregoing third photoresists41, the third filter portions42and the third spacer portions.

With further reference toFIGS. 2H and 21, the first photoresists21, the second photoresists31and the third photoresists41may be red, green and blue photoresists, respectively. As a preferred embodiment of the present invention, the first photoresists21, the second photoresists31and the third photoresists41on the substrate10have the same thickness L1. The first, the second and the third filter portions22,32,42that are overlapped with each other on the substrate10have a total thickness being equal to L1. However, the total thickness may not be equal to L1as long as the overlapped first, second and third filter portions22,32,42achieve a light-shielding effect.

In the present invention, the overlapped first, second and third filter portions22,32,42can respectively absorb light of different wavelengths so as to provide a light-shielding effect like black matrix. Besides, each of the first photoresists21is connected to a corresponding one of the first filter portions22; each of the second photoresists31is connected to a corresponding one of the second filter portions32; and each of the third photoresists41is connected to a corresponding one of the third filter portions42, so that it ensures that the overlapped first, second and third filter portions22,32,42are seamlessly connected to the first, the second or the third photoresists21,31,41without forming any seam that may lead to light leakage.

With further reference toFIG. 2J,FIG. 2Jis a cross-sectional view of the substrate10, the first, the second and third spacer portions after finishing the manufacturing process of the color filter. The overlapped first, second and third spacer portions on the substrate10have a total thickness that is equal to L2, wherein L2>L1. Hence, when constructing a liquid crystal display device, an effect can be achieved that a thin-film transistor substrate is spaced from the color filter of the present invention.

In a specific implementation process, please return toFIG. 2C, between two adjacent first photoresists21, when a first filter portion22, a first coating area23, another first filter portion22, a second coating area24and still another first filter portion22are formed in order along the direction “A”, a third coating area and still another filter portion22may be further formed following the order along the direction “A”, wherein the third coating area is used for forming a fourth photoresist, for example, a yellow photoresist. According to the above description, when forming the fourth photoresists, multiple fourth filter portions are correspondingly formed on the third filter portions42and multiple fourth spacer portions are correspondingly formed on the third spacer portions at the same time. Besides, the first, the second, the third and the fourth photoresists on the substrate10may have the same thickness L1. The first, the second, the third and the fourth filter portions that are overlapped with each other on the substrate10may have a total thickness being equal to L1. However, the total thickness may not be equal to L1as long as the overlapped first, second, third and fourth filter portions achieve a light-shielding effect. As a preferred embodiment of the present invention, the overlapped first, second, third and fourth spacer portions on the substrate10have a total thickness L3(not shown in the figures), wherein L3>L2, and L3>L1.

Furthermore, each of the fourth photoresists is connected to a correspondingly one of the fourth filter portions, so that it ensures that the overlapped first, second, third and fourth filter portions are seamlessly connected to the first, the second, the third and the fourth photoresists without forming any seam that may lead to light leakage.

The present invention further provides a color filter. The color filter is formed by the manufacturing method of color filter of the present invention. A detail structure of the color filter can be found in the above description in cooperation withFIGS. 2A to 21, no more tautology here.

Please refer toFIG. 3, whereinFIG. 3is a schematic view of a liquid crystal display device using the color filter of the present invention. In a specific implementation process, a TFT substrate50is attached to the color filter of the present invention and is spaced from the color filter by the third spacer portions of the color filter. A specific implementation can also be found in the above description, no more tautology here.

The present invention uses the material layers that are used for manufacturing red, green and blue photoresists to further form the overlapped first, second and third filter portions while manufacturing the red, green and blue photoresists. The first, the second and the third filter portions can respectively absorb light of different wavelengths so as to provide a light-shielding effect like black matrix, thus the overall manufacturing process does not need another specific photolithography process to manufacture a black matrix layer. Besides, in the processes of forming the first, the second and the third filter portions, the first, the second and the third spacer portions are correspondingly formed on and protruding from the top surface of the first, the second and the third filter portions so that the overall manufacturing process does not need another process to form spacers. Hence, material can be saved, production cost can be reduced, and the cycle time of the manufacturing process is shortened and thereby improving the production efficiency.