1. Field of the Invention
The present invention generally relates to a color resin composition and to a method of using the color resin composition to form multicolor color filters. In particular, the present invention is directed to a specially formulated color resin composition and to a method of using the color resin composition to form multicolor color filters by merely one single baking step.
2. Description of the Prior Art
A color filter is one of the critical components of a color display and the cost of the color filter is a relatively high factor of the total production cost of the color display. The function of the color filters is to display color images by adjusting the light form a light source of the backlight.
The conventional procedures for fabricating the color filters may be as follows. First, organic materials of different colors, such as red, green and blue, are formed in each pixel by lithographic and, exposure steps. After each lithographic or exposure step, a cleaning and brushing step is required to be done on the organic materials. However, peel-off or defects are often observed because organic materials of different colors are not robust enough to endure the damages of the cleaning step or brushing step after the organic materials of different colors undergo the lithographic or exposure steps. As a result, a thermal curing step must be introduced to bake the organic materials so as to make sure that the cleaning and brushing step are not going to do any damages on the developed organic materials, that is, the product at this stage—the color filters, after the lithographic or exposure steps but before the cleaning and brushing step.
Although the baking step may strengthen the robustness of the organic materials and ensures that the cleaning and brushing step may not collaterally damage the developed organic materials, some collateral problems still happen. For example, the organic materials finished at the first baking step must undergo two more baking steps than the organic materials finished at the third baking step. As far as the organic materials finished at the first baking step are concerned, the two additional baking steps, i.e. the two later baking steps, are not only totally unnecessary but are also energy-wasting. In such a way, each baking step in one aspect increases the thermal budget and in another aspect may potentially once more alter the chemical or the physical properties of the organic materials.
Given the above, a novel method for making multicolor color filters is still needed to improve the current fabricating process to further cut the thermal budget.
In the light of this, the present invention proposes a novel method for forming multicolor color filters. The novel method for forming multicolor color filters of the present invention not only omits unnecessary baking steps but also makes the multicolor color filters fabricated by the present invention not substantially distinct from those fabricated by a conventional process. In addition, the ordinary and necessary cleaning and brushing steps after the lithographic or exposure steps do not substantially harm the originally formulated color filters of the present invention and do not cause any peel-off or defects. To sum up, the novel method of the present invention is indeed able to improve the current fabricating process.
The present invention in a first aspect proposes a novel method for forming multicolor color filters. First, a substrate is provided. Second, a first patterned color layer is formed on the substrate. The first patterned color layer has a first color. Then, a second patterned color layer is formed on the substrate which already has the first patterned color layer. The second patterned color layer has a second color. Next, a third patterned color layer is formed on the substrate which simultaneously has the first patterned color layer and the second patterned color layer. The third patterned color layer has a third color and the first color, the second color and the third color being mutually different. The positions of the first patterned color layer, the second patterned color layer and the third patterned color layer are respectively different. Later, the first patterned color layer, the second patterned color layer and the third patterned color layer together are simultaneously baked to turn into a first pixel color layer of the multicolor color filters, into a second pixel color layer of the multicolor color filters and into a third pixel color layer of the multicolor color filters.
In one embodiment of the present invention, at least one of a printing screen process and a spraying process is used to form the first patterned color layer, the second patterned color layer or the third patterned color layer.
In another embodiment of the present invention, the formation of the first patterned color layer may further include the following steps. First, a first color photoresist layer is formed on the substrate. Second, the first color photoresist layer is exposed and developed to form the first patterned color layer.
In another embodiment of the present invention, the present invention may further include the following step after the formation of the first patterned color layer. The first patterned color layer is washed without substantially being damaged.
In another embodiment of the present invention, the present invention may further include the following step after the formation of the first patterned color layer. The first patterned color layer is brushed without being substantially damaged.
In another embodiment of the present invention, the formation of the second patterned color layer may further include the following steps. First, a second color photoresist layer is formed on the substrate. Second, the second color photoresist layer is exposed and developed to form the second patterned color layer.
In another embodiment of the present invention, the present invention may further include the following step after the formation of the second patterned color layer. The second patterned color layer is washed without substantially being damaged.
In another embodiment of the present invention, the present invention may further include the following step after the formation of the second patterned color layer. The second patterned color layer is brushed without being substantially damaged.
In another embodiment of the present invention, the formation of the third patterned color layer may further include the following steps. First, a third color photoresist layer is formed on the substrate. Second, the third color photoresist layer is exposed and developed to form the third patterned color layer.
In another embodiment of the present invention, the present invention may further include the following step after the formation of the third patterned color layer. The third patterned color layer is washed without substantially being damaged.
In another embodiment of the present invention, the present invention may further include the following step after the formation of the third patterned color layer. The third patterned color layer is brushed without being substantially damaged.
In another embodiment of the present invention, the first patterned color layer, the second patterned color layer and the third patterned color layer are baked for around 20-40 minutes at a temperature around 200° C.-240° C.
In another embodiment of the present invention, the first color, the second color and the third color are selected from a group consisting of red, green and blue.
In another embodiment of the present invention, the first patterned color layer, the second patterned color layer and the third patterned color layer may respectively and independently include:
a hydrophobic resin of 15%-25% of a total weight;
an acrylate reactive monomer of 10%-20% of the total weight;
a photo-initiator of 0.5%-3% of the total weight; and
a solvent of 55%-75% of the total weight.
In another embodiment of the present invention, at least one of the first patterned color layer, the second patterned color layer and the third patterned color layer further includes:
an additive up to 3% of the total weight.
The present invention in a second aspect proposes a color resin composition. The color resin composition includes:
a hydrophobic resin of 15%-25% of a total weight;
an acrylate reactive monomer of 10%-20% of the total weight;
a photo-initiator of 0.5%-3% of the total weight; and
a solvent of 55%-75% of the total weight.
In one embodiment of the present invention, the hydrophobic resin is selected from the following compound:
In another embodiment of the present invention, the acrylate reactive monomer includes:
wherein a is 6 and b is 0.
In another embodiment of the present invention, the color resin composition of the present invention may further include:
an additive up to 3% of the total weight.
In another embodiment of the present invention, the additive includes a thiol compound.
In another embodiment of the present invention, the color resin composition may be red, green or blue.
In another embodiment of the present invention, the solvent may include at least one of ethyl 3-ethoxypropionate, 1-methoxy-2-propyl acetate, 3-methoxybutyl acetate and cyclohexanone.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
The novel method for forming multicolor color filters of the present invention may omit unnecessary baking steps and save the thermal budget. At the same time, the multicolor color filters made by the present invention are not substantially distinct from those made by a conventional process. In addition, the color filters of the present invention have original formulation to be able to endure the ordinary and necessary cleaning and brushing steps after the lithographic or exposure steps without being substantially damaged or peeled off.
The present invention in a first aspect provides a robust color resin composition. The robust color resin composition of the present invention has a higher mechanical strength and outstanding hydrophobic property and is able to endure the direct contact and scrub of the detergent and the brushes without causing any peel-off or defects. The color resin composition of the present invention includes a hydrophobic resin, an acrylate reactive monomer, a photo-initiator and a solvent. The hydrophobic resin is usually 15%-25% of a total weight, preferably 17% of the total weight. The hydrophobic resin may have organic hydrophobic molecules. A suitable hydrophobic resin may be the compound as shown in
The acrylate reactive monomer is usually 10%-20% of the total weight, preferably 16% of the total weight. The acrylate reactive monomer is usually an acrylate compound with active double-bound(s) which is capable of polymerizing. A suitable acrylate reactive monomer may be:
a may be 6 and b may be 0.
The photo-initiator is usually 0.5%-3% of the total weight, preferably 2.2% of the total weight, to initiate a photo-polymerization reaction. A better photo-initiator is sensitive. For example, it has an extraordinarily high absorption to a wavelength of 365 nm. Some suitable photo-initiators may be the compounds as shown in
The solvent usually has a larger weight percentage of the total composition. For example, the solvent may be 55%-75% of the total weight, preferably 62.8% of the total weight. The solvent is usually an inert liquid to uniformly dissolve the above ingredients. The solvent may be polyethers. A suitable polyether may be ethyl 3-ethoxypropionate, 1-methoxy-2propyl acetate, 3-methoxybutyl acetate or cyclohexanone.
In one embodiment of the present invention, the color resin composition of the present invention may optionally include an additive up to 3% of the total weight, to improve or to adjust the properties of the color resin composition of the present invention. For example, the additive may include a thiol compound of the following chemical structure (1) to enhance the photo-polymerization reaction:
Z may be NH or S.
The color resin composition of the present invention may have any one of the colors such as red, green or blue. The color resin composition of the present invention may enhance the cross-linking of the photoresist reaction, the photoresist hydrophobic property, to avoid possible light-leaking or peeling after the development procedure. As a result, the patterned color layers of the present invention are able to have sufficient mechanical strength and hydrophobic property to endure the damages of the detergent and brushes during the washing or the brushing step so the patterned color layers (the photoresist) of the present invention do not peel off or have defects after the washing or the brushing step.
The present invention in a second aspect provides a novel method for forming multicolor color filters.
The first patterned color layer 110 may be a photoresist material of a certain color and have a pre-determined pattern by some lithographic and exposure procedures. For example, please refer to
Optionally, please refer to
Next, as shown in
The second patterned color layer 120 may also be a photoresist material of a certain color, such as one of red, green and blue, and have a pre-determined pattern by some lithographic and exposure procedures. For example, please refer to
Optionally, please refer to
Afterwards, as shown in
The third patterned color layer 130 may also be a photoresist material of a certain color, such as one of red, green and blue, and have a pre-determined pattern by some lithographic and exposure procedures. For example, please refer to
Optionally, please refer to
Providing the exposure and development procedures are not used to form the patterned color layers, as shown in
After that, please refer to
For example, the first patterned color layer 110, the second patterned color layer 120 and the third patterned color layer 130 may be baked together under a temperature of about 200° C.-240° C. for about 20-40 minutes to simultaneously obtain a thermally cured first pixel color layer 112, second pixel color layer 122 and third pixel color layer 132 of the needed multicolor color filters. Preferably, the first patterned color layer 110, the second patterned color layer 120 and the third patterned color layer 130 before the baking step as well as the first pixel color layer 112, second pixel color layer 122 and third pixel color layer 132 after the baking step do not directly contact or overlap one another. The novel method for forming multicolor color filters of the present invention may omit unnecessary baking steps to save a lot of thermal budget. At the same time, the differences or distinctions between the multicolor color filters obtained by the novel method of the present invention and by conventional methods are not substantial as far as the quality or the color is concerned.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Number | Date | Country | Kind |
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100134416 | Sep 2011 | TW | national |