A weakly alkaline developer for TFT-LCD color filter manufacturing process

Abstract

The present invention discloses a weakly alkaline developer for the process of TFT-LCD color filter. Based on the sum of weight percentages being 100%, the raw materials used in the developer and their respective weight percentages are as follows: alkaline substance 4-15%, conjugate structure-containing dispersant 5-15%, solubilizer 0.5-5%, and the balance being water. The developer prepared by the present invention has the advantages of weak alkalinity, less foam, clear developing pattern, no photoresist residue, long service life, etc., and is mainly used for the development of negative photoresist in display panels.

Description

Technical Field

[0001] The present invention belongs to the field of wet electronic chemicals, and particularly relates to a weakly alkaline developer for the TFT-LCD color filter manufacturing process. Background Art

[0002] TFT-LCD has the advantages of good use characteristics, wide application range, high degree of automation in manufacturing technology, and convenience for large-scale industrial production. Moreover, TFT-LCD is easy to integrate and upgrade, and is a perfect combination of large-scale semiconductor integrated circuit technology and light source technology, with great development potential. The manufacturing process of TFT-LCD includes array, color filter (CF), cell, and module. Among them, the CF process plays an important role in the entire TFT-LCD manufacturing process.

[0003] The photolithography process in the CF process generally includes spin coating, pre-baking, exposure, development, and post-baking, etc. Among them, the development process is that the alkaline developer reacts chemically with the photoresist, that is, the unexposed part is dissolved, and the exposed photoresist is retained, so as to transfer the light-transmitting area pattern on the mask plate to the photoresist. The main components of the photoresist are viscous polymers (mostly acrylate substances), crosslinking agents, photoinitiators, organic solvents, dispersants, and pigment molecules. The compatibility between the black matrix BM and RGB photoresist and the developer in the CF process is very important. During the development process, the photoresist and the developer must react completely quickly without leaving photoresist residues.

[0004] At present, the developers circulating on the market are mainly strong alkaline developers represented by KOH, and the main components include inorganic strong bases, surfactants, and water. Among them, the inorganic strong base has an obvious dissolving effect on the photoresist, but the strong base system has relatively high requirements for the production process and the use process. Relatively speaking, the weakly alkaline condition is more mild and has less harm to the human body and equipment. Summary of the Invention

[0005] In order to enrich the types of weakly alkaline developers on the market, the present invention provides a weakly alkaline developer for the TFT-LCD color filter manufacturing process, which contains a dispersant with a conjugated structure prepared by modifying biphenyltriazole alcohol. Compared with the existing dispersants, the novel dispersant provided by the present invention has better performance, can maintain the uniform state of the developer, improve the dispersibility of the photoresist in the system, and prevent aggregation adsorption and the generation of foam.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A weakly alkaline developer for TFT-LCD filter manufacturing process. Based on the total weight percentage being 100%, the raw materials used and their respective weight percentages are: alkaline substances 4 - 15%, dispersant with conjugated structure 5 - 15%, solubilizer 0.5 - 5%, and the balance being water.

[0008] Furthermore, the chemical structural formula of the dispersant with conjugated structure is:

[0009] , where m and n are integers from 0 to 200 and not equal to 0.

[0010] The reaction process for preparing the dispersant with conjugated structure is: ;

[0011] The preparation steps are as follows:

[0012] (1) Mix a certain amount of bitertanol and catalyst, keep the temperature at 145 - 155 °C for dehydration treatment for 20 min. After replacing the system gas with nitrogen 5 times, add a small amount of propylene oxide and conduct an induction reaction at 150 °C and a pressure less than 0.3 MPa. When the reaction pressure drops significantly and the temperature rises sharply, gradually add the remaining propylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure less than 0.3 MPa for reaction until the reaction pressure no longer decreases, and then continue to maintain the temperature for 30 min to obtain an intermediate product;

[0013] (2) Add a small amount of ethylene oxide to the obtained intermediate product and conduct an induction reaction at 150 °C and a pressure less than 0.3 MPa. When the pressure drops significantly and the temperature rises sharply, gradually add the remaining ethylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure less than 0.3 MPa for reaction until the reactor pressure no longer decreases, and then continue to maintain the temperature for 30 min. Then, reduce the pressure to remove the unreacted monomers to obtain the dispersant with conjugated structure.

[0014] The molar ratio of bitertanol to propylene oxide and ethylene oxide used in the operation is 1:(10 - 200):(5 - 200).

[0015] The catalyst is one or several of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, potassium methoxide; its dosage is 50 - 100 ppm of the total mass of bitertanol, ethylene oxide, and propylene oxide used.

[0016] Furthermore, the alkaline substances are one or several of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium metasilicate, sodium hydrogen phosphate, potassium phosphate, sodium hypochlorite, potassium hypochlorite, sodium dihydrogen sulfate, ammonium carbonate, sodium silicate.

[0017] Furthermore, the solubilizer is one or more of Tween-20, Tween-80, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene-polyoxypropylene ether, sodium dodecyl sulfate, and isomeric alcohol polyoxyethylene ether.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) The developer of the present invention is a weakly alkaline system. The present invention abandons the currently popular KOH-based inorganic strong base system on the market and uses a weakly alkaline inorganic salt as the alkaline additive, which is safer, more environmentally friendly, and less harmful to the human body and production equipment.

[0020] (2) The developer of the present invention uses a self-synthesized dispersant containing a conjugated structure. Compared with traditional dispersants, the dispersant prepared in the present invention adds a conjugated structure to the molecule, making the planarization degree of the entire molecular structure higher, and thus the dispersion effect can be better.

[0021] (3) On the basis of reducing hazards, the developer of the present invention can effectively reduce problems such as incomplete development and residues in development, and a substrate with clear patterns, complete edges, and no photoresist residue can be obtained, and the development service life can be improved. Detailed implementation mode

[0022] A weakly alkaline developer for TFT-LCD color filter manufacturing process, calculated by the sum of weight percentages being 100%, the raw materials used and the weight percentages of each raw material are: alkaline substance 4-15%, dispersant containing conjugated structure 5-15%, solubilizer 0.5-5%, and the balance is water.

[0023] Among them, the alkaline substance is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium metasilicate, sodium hydrogen phosphate, potassium phosphate, sodium hypochlorite, potassium hypochlorite, sodium dihydrogen sulfate, ammonium carbonate, and sodium silicate. The solubilizer is one or more of Tween-20, Tween-80, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene-polyoxypropylene ether, sodium dodecyl sulfate, and isomeric alcohol polyoxyethylene ether.

[0024] The chemical structural formula of the dispersant containing a conjugated structure is:

[0025] , Among them, m and n are integers from 0 to 200 and not 0; the preparation steps are as follows:

[0026] (1) Mix a certain amount of bitertanol and a catalyst, dehydrate at a temperature of 145 - 155°C for 20 min. After replacing the system gas with nitrogen 5 times, add a small amount of propylene oxide, and carry out an induction reaction at 150°C and a pressure less than 0.3 MPa. When the reaction pressure drops significantly and the temperature rises sharply, gradually add the remaining propylene oxide. After adding, keep the temperature at 145 - 165°C and the pressure less than 0.3 MPa for the reaction until the reaction pressure no longer decreases, and then continue to maintain the temperature for 30 min to obtain an intermediate product;

[0027] (2) Add a small amount of ethylene oxide to the obtained intermediate product, and carry out an induction reaction at 150°C and a pressure less than 0.3 MPa. When the pressure drops significantly and the temperature rises sharply, gradually add the remaining ethylene oxide. After adding, keep the temperature at 145 - 165°C and the pressure less than 0.3 MPa for the reaction until the reactor pressure no longer decreases, and then continue to maintain the temperature for 30 min. Then reduce the pressure to remove the unreacted monomers to obtain the dispersant containing a conjugated structure.

[0028] The molar ratio of bitertanol to propylene oxide and ethylene oxide used in the operation is 1:(10 - 200):(5 - 200).

[0029] The catalyst is one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, and potassium methoxide; its dosage is 50 - 100 ppm of the total mass of bitertanol, ethylene oxide, and propylene oxide used.

[0030] To make the content of the present invention easier to understand, the technical solutions of the present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0031] Example 1

[0032] (1) Add 5 kg of bitertanol and 0.1 g of sodium hydroxide to a reactor, dehydrate at a temperature of 150°C for 20 min. At the same time, after replacing the system gas with nitrogen 5 times, add 100 g of propylene oxide, and carry out an induction reaction at a temperature of 140°C and a pressure less than 0.3 MPa. When the temperature rises sharply and the pressure drops significantly, continue to add 5 kg of propylene oxide. After adding, keep the temperature at 145 - 165°C and the pressure less than 0.3 MPa until the reaction pressure no longer decreases, and then continue to maintain the temperature for 30 min to obtain an intermediate product.

[0033] (2) Maintain the reactor temperature at 150 °C, and continue to add 100 g of ethylene oxide to the obtained intermediate product. Conduct an induction reaction while maintaining the pressure below 0.3 MPa. When the temperature rises sharply and the pressure drops significantly, continue to add 10 kg of ethylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure below 0.3 MPa until the reaction pressure no longer decreases. Then, keep the temperature for 30 min and remove the unreacted monomers under reduced pressure to obtain a dispersant containing a conjugated structure.

[0034] Example 2

[0035] (1) Add 5 kg of bitertanol and 0.1 g of potassium methoxide to the reactor. Keep the temperature at 150 °C for dehydration for 20 min. At the same time, displace the system gas with nitrogen 5 times, then add 150 g of propylene oxide. Conduct an induction reaction under the conditions of a temperature of 145 °C and a pressure below 0.3 MPa. When the temperature rises sharply and the pressure drops significantly, continue to add 10 kg of propylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure below 0.3 MPa until the reaction pressure no longer decreases. Then, keep the temperature for 30 min to obtain an intermediate product.

[0036] (2) Maintain the reactor temperature at 145 °C, and continue to add 100 g of ethylene oxide to the obtained intermediate product. Conduct an induction reaction while maintaining the pressure below 0.3 MPa. When the temperature rises sharply and the pressure drops significantly, continue to add 4 kg of ethylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure below 0.3 MPa until the reaction pressure no longer decreases. Then, keep the temperature for 30 min and remove the unreacted monomers under reduced pressure to obtain a dispersant containing a conjugated structure.

[0037] Example 3

[0038] (1) Add 5 kg of bitertanol and 0.1 g of sodium ethoxide to the reactor. Keep the temperature at 150 °C for dehydration for 20 min. After displacing the system gas with nitrogen 5 times, add 150 g of propylene oxide. Conduct an induction reaction under the conditions of a temperature of 150 °C and a pressure below 0.3 MPa. When the temperature rises sharply and the pressure drops significantly, continue to add 8 kg of propylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure below 0.3 MPa until the reaction pressure no longer decreases. Then, keep the temperature for 30 min to obtain an intermediate product.

[0039] (2) Maintain the reactor temperature at 145 °C, and continue to add 100 g of ethylene oxide to the obtained intermediate product. Conduct an induction reaction while maintaining the pressure below 0.3 MPa. When the temperature rises sharply and the pressure drops significantly, continue to add 8 kg of ethylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure below 0.3 MPa until the reaction pressure no longer decreases. Then, continue to maintain the temperature for 30 min, and remove the unreacted monomers under reduced pressure to obtain a dispersant containing a conjugated structure.

[0040] Example 4

[0041] Control the mass of propylene oxide during polymerization to 7 kg, and keep the other conditions the same as in Example 1.

[0042] Example 5

[0043] Control the mass of ethylene oxide during polymerization to 11 kg, and keep the other conditions the same as in Example 2.

[0044] Application Example

[0045] According to the formulation in Table 1, use the dispersants prepared in each example to prepare a weakly alkaline developer. That is, according to the content in Table 1, add deionized water to a stirring kettle with a reaction volume of 100 kg, start stirring, slowly add the alkaline substance, stir for 30 min until it is completely dissolved, then add the dispersant, stir for 15 min, and finally add the solubilizer and stir for 20 min to obtain the corresponding weakly alkaline developer. The stirring rate of the stirring kettle is 30 rpm, and the stirring temperature is controlled below 50 °C.

[0046] Table 1

[0047]

[0048] Performance Test:

[0049] To verify the performance of the above developer, it is measured through the following experimental scheme.

[0050] 1. Preparation of Glass Substrate

[0051] Prepare glass substrate samples. After cleaning the glass substrates with a special cleaning agent, rinse them with ultrapure water and dry them with nitrogen. Spin-coat a 1.0 μm thick BM negative photoresist or R, G, B photoresist on each glass substrate using a spin coater. After evacuating most of the solvent, perform a pre-bake at 110 °C in an oven for 100 s, and then use a pattern mask for exposure to transfer the pattern on the mask plate to the glass substrate.

[0052] 2. Development Test

[0053] Dilute the prepared developer 20 - 60 times with ultrapure water, control the temperature of the liquid medicine at 23 °C, spray the diluted developer on the glass substrate coated with photoresist with a constant pressure, the spraying time is 50 s, then wash with ultrapure water and dry with nitrogen. Observe with an optical microscope and an electron microscope to confirm whether the developed pattern is clear, whether there is photoresist residue, whether the edge of the pattern is complete, whether there is a burr phenomenon, how many glass substrates are sprayed before obvious photoresist residue appears, and the service life of the developer. The results are shown in Table 2.

[0054] Table 2

[0055]

[0056] It can be seen from the results in Table 2 that the developer prepared in the embodiment is clear, transparent, stable in nature, not prone to precipitation, and still has the advantages of appropriate development speed, clear pattern, complete edge, no photoresist residue, and long service life on the basis of reducing hazards.

[0057] The above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. A weakly alkaline developer for TFT-LCD filter manufacturing process, characterized in that by weight percentage sum of 100%, the raw materials and their weight percentages in the weakly alkaline developer are as follows: alkaline substance 4 - 15%, dispersant with conjugated structure 5 - 15%, solubilizer 0.5 - 5%, and the balance is water; The chemical structural formula of the dispersant with conjugated structure is: ， wherein, m and n are integers from 0 to 200 and not 0; The alkaline substance is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium metasilicate, sodium hydrogen phosphate, potassium phosphate, sodium hypochlorite, potassium hypochlorite, sodium dihydrogen sulfate, ammonium carbonate, sodium silicate.

2. The weakly alkaline developer according to claim 1, characterized in that: The preparation steps of the dispersant with conjugated structure are as follows: (1) Mix a certain amount of bitertanol and catalyst, keep the temperature at 145 - 155 °C for dehydration treatment for 20 min, after replacing the system gas with nitrogen for 5 times, add a small amount of propylene oxide, and carry out an induction reaction at 150 °C and a pressure less than 0.3 MPa. When the reaction pressure drops significantly and the temperature rises sharply, gradually add the remaining propylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure less than 0.3 MPa for reaction until the reaction pressure no longer decreases, and then keep the temperature for 30 min to obtain an intermediate product; (2) Add a small amount of ethylene oxide to the obtained intermediate product, and carry out an induction reaction at 150 °C and a pressure less than 0.3 MPa. When the pressure drops significantly and the temperature rises sharply, gradually add the remaining ethylene oxide. After adding, keep the temperature at 145 - 165 °C and the pressure less than 0.3 MPa for reaction until the reactor pressure no longer decreases, and then keep the temperature for 30 min, and then reduce the pressure to remove the unreacted monomers to obtain the dispersant with conjugated structure.

3. The weakly alkaline developer according to claim 2, characterized in that: The molar ratio of bitertanol used to propylene oxide and ethylene oxide is 1:(10 - 200):(5 - 200).

4. The weakly alkaline developer according to claim 2, characterized in that: The catalyst is one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium ethoxide, potassium methoxide; and its dosage is 50 - 100 ppm of the total mass of bitertanol, ethylene oxide, and propylene oxide used.

5. The weakly alkaline developer according to claim 1, characterized in that: The solubilizer is one or more of Tween - 20, Tween - 80, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene - polyoxypropylene ether, sodium dodecyl sulfate, isomeric alcohol polyoxyethylene ether.

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