Long-service-life developing solution for CF-section negative photoresist development and preparation method of long-service-life developing solution

Abstract

The invention relates to the technical field of developing solutions, in particular to a long-service-life developing solution for CF section negative photoresist development and a preparation method of the long-service-life developing solution. The long-life developing solution is prepared from the following components: inorganic alkali, a nonionic surfactant, alkynol, polyethylene glycol and high-purity water. By introducing a synergistic system of alkynol and polyethylene glycol, absorption of alkali liquor to CO2 in air is remarkably inhibited while efficient and lasting defoaming is realized, reduction of conductivity is fundamentally slowed down, the service life of a developing solution is effectively prolonged, the stability of a developing process is improved, the method is completely compatible with an existing production line, and the method is suitable for industrial production. The method has an important practical value.

Description

Technical Field

[0001] This invention relates to the field of developer technology, specifically to a long-life developer for CF segment negative photopolymer development and its preparation method. Background Technology

[0002] Thin-film transistor liquid crystal displays (TFT-LCDs) offer advantages such as low cost, high brightness, and low power consumption, making them widely used in televisions, computers, mobile phones, and automotive displays. Their manufacturing process mainly includes four stages: array, color filter (CF), cell assembly, and module assembly. Among these, the CF process is particularly critical to the quality of the finished product. The CF process encompasses processes such as the black matrix (BM), color resist (RGB), protective layer (OC), and inductively coupled electrode (ITO). Except for ITO, all other patterning processes require the use of a developer. Because the CF process uses negative photoresist, a negative photoresist developer is used. A typical process flow includes cleaning, photoresist coating, pre-baking, exposure, development, and post-baking. The developer is used to remove photoresist from unexposed areas, ultimately forming the desired pattern. Key performance indicators for this process include linewidth (CD), straightness, film thickness uniformity, and surface smoothness. The conductivity in the developer is a core parameter for monitoring the concentration of potassium hydroxide (KOH). If the conductivity decreases too rapidly, it indicates a rapid decrease in the KOH concentration. - It reacts with carbon dioxide (CO2) in the air to form potassium carbonate (K2CO3), which weakens the developing ability and may cause problems such as incomplete development and linewidth fluctuations.

[0003] Most commercially available developer solutions consist of KOH, surfactants, and water. The concentrate is diluted before being used on the production line. During use, the alkaline solution readily reacts with CO2, causing a decrease in conductivity; excessively low concentrations will lead to developer failure. Since production line equipment needs to operate continuously, even without substrate transport, slowing down conductivity decay during periods without wafers is crucial for reducing developer consumption. Furthermore, linewidth stability is extremely important during development; a sudden drop in conductivity directly affects uniformity.

[0004] In the existing technology, several patents have proposed improvement solutions, but all have limitations in their applicability. For example, patent 201811345668.4 discloses a developer solution with sodium carbonate, potassium carbonate, and organic alkaloids as the main components. Although it can reduce the frequency of tank changes, it is mainly suitable for printed circuit boards and not for color filter processes. Patent 202410697117.3 proposes a low-foaming developer solution using acetylation glycol ether-modified organosilicon as the defoaming component. However, organosilicon defoamers are difficult to pass through the photoresist (PR) filter cartridge in the color filter production line, and their durability is poor in alkaline environments. Another patent, 202211412813.2, introduces a long-life formula for color filters suitable for low-concentration developer solutions. It extends the service life through specific nonionic surfactants and dispersants, but its synthesis process is complex and difficult to implement.

[0005] Therefore, there is an urgent need to develop a high-performance developer that has good CO2 stability, long service life, can be directly used in production lines, and is compatible with existing color filter processes and filtration systems. Summary of the Invention

[0006] In view of this, the present invention proposes a long-life developer for CF segment negative photoresist development and its preparation method. By introducing a synergistic system of alkynyl alcohol and polyethylene glycol, efficient and long-lasting defoaming is achieved while significantly inhibiting the absorption of CO2 from the air by the alkaline solution. This design fundamentally slows down the decrease in conductivity, effectively extends the developer life, improves the stability of the development process, and is fully compatible with existing production lines, thus possessing significant practical value. The technical solution of the present invention is implemented as follows: In a first aspect, the present invention proposes a long-life developer for developing negative photoresist in the CF segment, comprising the following components: inorganic alkali, nonionic surfactant, alkynyl alcohol, polyethylene glycol and high-purity water.

[0007] Specifically, the inorganic alkali is the main substance that reacts with the photoresist (PR); the nonionic surfactant includes a mixture of composite epoxy alkyl surfactants (ADD-A), which mainly plays a penetrating role and provides a reaction channel for the reaction of alkaline substances such as KOH with PR, while preventing PR from being redeposited onto the substrate.

[0008] Preferably, the mass percentage of the alkynol is 0.5-10% based on a total mass of 100%.

[0009] Preferably, the polyethylene glycol accounts for 2-10% of the total mass.

[0010] More preferably, the mass ratio of the alkynol to polyethylene glycol is 1:(1.5-8).

[0011] Specifically, if the ratio is too low, too much polyethylene glycol may lead to excessive viscosity, affecting the defoaming speed; if the ratio is too high, too much acetylsol may be present, but it is easily volatile and the effect is not lasting.

[0012] Specifically, this invention incorporates ADD-A, a polyoxyethylene aryl ether and a nonionic surfactant. ADD-A penetrates and prevents photoresist adsorption onto the substrate, generating significant foam during the spraying process. This invention addresses this issue through a multi-mechanism solution built upon the synergistic effect of alkynyl alcohol and polyethylene glycol. Regarding defoaming, alkynyl alcohol molecules rapidly arrange themselves at the gas-liquid interface to form a dense monolayer, effectively disrupting the foam structure and reducing the contact area between CO2 and the developer at its source. In terms of stability and durability, polyethylene glycol not only enhances the spreading efficiency of alkynyl alcohol at the interface through physical adsorption but also significantly reduces the dissolution rate of CO2 in the system by increasing solution viscosity, while effectively improving the retention of alkynyl alcohol in the solution, preventing its degradation due to volatilization. The synergistic effect of these two components effectively suppresses KOH consumption and conductivity decline, thereby significantly improving the developer's lifespan and process stability.

[0013] More preferably, the molecular weight of the polyethylene glycol is 400-6000.

[0014] Specifically, if the molecular weight is too small, the retention and thickening properties will be insufficient; if the molecular weight is too large, it may affect the solubility in the developer and the spreading speed at the gas-liquid interface; a specific molecular weight range can achieve the optimal balance.

[0015] Preferably, based on a total mass percentage of 100%, the nonionic surfactant accounts for 8-30% of the total mass, and the inorganic base accounts for 4-7% of the total mass.

[0016] Preferably, the alkynols include 2-propyn-1-ol, 3-butyn-1-ol, 2-butyn-1,4-diol, 2-hexyn-1-ol, or 3-hexyn-2,5-diol.

[0017] Preferably, the inorganic base includes KOH or NaOH.

[0018] Preferably, the nonionic surfactant includes a complex epoxy alkyl surfactant (ADD-A).

[0019] In a second aspect, the present invention provides a method for preparing the high-lifetime developer described in the first aspect, comprising the following steps: adding the inorganic alkali, nonionic surfactant, and alkynol sequentially to high-purity water, stirring until completely dissolved, then adding polyethylene glycol, stirring thoroughly, and stirring until uniform to obtain the high-lifetime developer.

[0020] Thirdly, the present invention provides an application of the high-lifetime developer described in the first aspect in CF segment negative photopolymer development.

[0021] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention uses non-organosilicon and non-polyether alkynol defoamer, which can reduce foam generation from the source. The reduction of foam effectively reduces the contact area between the developer and the air, thereby significantly slowing down CO2 absorption and related KOH consumption reaction, providing the first layer of protection for maintaining stable conductivity.

[0022] (2) This invention innovatively utilizes the synergistic effect of alkynol and polyethylene glycol. Polyethylene glycol can not only increase the viscosity of the solution and reduce the dissolution rate of CO2 in the liquid, but also improve the retention of small molecule alkynol through physical adsorption and prevent its volatilization and failure. This dual mechanism of "physical barrier" and "chemical retention" effectively inhibits the excessively rapid decrease in conductivity.

[0023] (3) The defoaming ingredients selected in this invention avoid the risk of clogging of the production line filter element by organosilicon substances, and ensure good compatibility with existing color film production line equipment and filtration system; at the same time, the formula is simple and does not require a complicated synthesis process, which is convenient for production preparation and on-site operation and maintenance.

[0024] (4) This invention can extend the effective life of the developer as a whole and reduce the frequency of tank changes. Its core value lies in ensuring the uniformity and stability of the developing linewidth, thereby improving product yield and reducing production costs. Detailed Implementation

[0025] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In this document, the terms “containing,” “comprising,” or “including” are open-ended expressions, meaning they include the contents specified in this invention but do not exclude other aspects.

[0028] In this document, the terms “optional,” “optionally,” or “optional” generally refer to an event or condition that may, but may not, occur, and the description includes both cases in which the event or condition occurs and cases in which the event or condition does not occur.

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0030] All materials used in this invention were purchased from the market. Specifically, ADD-A (RG) was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.; KOH (RG), 2,4-hexadiyne-1,6-diol (RG), 2-butyn-1,4-diol (RG), 3-butyn-1-ol (RG), and 3-hexyn-1-ol (RG) were all purchased from Titan Technology.

[0031] Table 1. Raw materials and proportions of developing solutions in the embodiments and comparative examples of the present invention.

[0032] According to the drug solution ratios of the examples and comparative examples in Table 1 above, 5 kg of developer solution was prepared. The specific steps were as follows: under stirring conditions, KOH, ADD-A, alkynol and polyethylene glycol were added to high-purity water in sequence, and the mixture was stirred evenly to obtain the high-lifetime developer solution.

[0033] Since the developing solution used in the production line is diluted to a KOH concentration of 0.043%, the aforementioned developing solution was also diluted to a KOH concentration of 0.043% and sprayed in the developing machine to compare the effectiveness of the developing solution. Using a mini developing machine, 5 kg of developing solution prepared in the above examples and comparative examples were added respectively, circulated at 23°C, and the conductivity (conductivity corresponds to KOH concentration) was tested at regular intervals. The rate of decrease in the conductivity of the developing solution was observed, as shown in Table 2. Comparative Example 7 showed stratification and could not form a stable solution, therefore it could not be tested.

[0034] Table 2. Test data on the conductivity stability of the developer solutions prepared in the embodiments and comparative examples of the present invention.

[0035] Comparative Example 1 showed a significant reduction in the lifespan of the developer without the addition of alkynol and polyethylene glycol. This was because the alkali in the developer solution readily reacted with CO2 in the air, causing the alkali concentration to drop too quickly and affecting the lifespan of the developer solution.

[0036] Comparative Examples 2 and 3 demonstrate that alkynyl alcohol and polyethylene glycol work synergistically, and adding only one has no significant effect, because adding one can only reduce foaming or increase viscosity, and has a weak effect on reducing CO2 dissolution.

[0037] Comparative Examples 4 and 5 demonstrate that the ratio of alkynyl alcohol to polyethylene glycol has an impact. Alkynyl alcohol is easily volatile during use, and the addition of polyethylene glycol has an inhibitory effect on the volatility of alkynyl alcohol. If the proportion of polyethylene glycol is too low, the inhibitory effect will be insufficient and thus it will not be able to prevent CO2 dissolution. If the proportion of polyethylene glycol is too high, the viscosity will be too high, which will affect the defoaming speed and thus affect the conductivity, causing it to drop too quickly.

[0038] Comparative Examples 6 and 7 demonstrate that the molecular weight of polyethylene glycol has an impact. If the molecular weight of polyethylene glycol is too large, it needs to be heated to dissolve, but the developer will separate when the temperature is increased. If the molecular weight is too small, the viscosity-increasing effect is insufficient and the desired synergistic effect cannot be achieved.

[0039] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A high-lifetime developer for CF segment negative photopolymer development, characterized in that, It includes the following components: inorganic base, nonionic surfactant, alkynol, polyethylene glycol and high-purity water.

2. The long-life developer according to claim 1, characterized in that, The mass percentage of the alkynol is 0.5-10% based on a total mass of 100%.

3. The long-life developer according to claim 1, characterized in that, The polyethylene glycol accounts for 2-10% of the total mass.

4. The long-life developer according to claim 1, characterized in that, The mass ratio of the alkynol to polyethylene glycol is 1:(1.5-8).

5. The long-life developer according to claim 1, characterized in that, Based on a total mass of 100%, the nonionic surfactant accounts for 8-30% of the mass, and the inorganic base accounts for 4-7% of the mass.

6. The long-life developer according to claim 1, characterized in that, The alkynols include 2-propyn-1-ol, 3-butyn-1-ol, 2-butyn-1,4-diol, 2-hexyn-1-ol, or 3-hexyn-2,5-diol.

7. The long-life developer according to claim 1, characterized in that, The inorganic base includes KOH or NaOH.

8. The long-life developer according to claim 1, characterized in that, The nonionic surfactant includes a mixture of complex epoxy alkyl surfactants.

9. A method for preparing a long-life developer as described in any one of claims 1 to 8, characterized in that, Includes the following steps: The inorganic alkali, nonionic surfactant, and alkynol are added sequentially to high-purity water. After the mixture is completely dissolved, polyethylene glycol is added and stirred thoroughly until homogeneous to obtain the high-lifetime developer.

10. The application of a high-lifetime developer as described in any one of claims 1 to 8 in CF segment negative photopolymer development.

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