A CF process negative photoresist rework solution and its preparation method and application

Abstract

The present invention provides a CF process negative photoresist rework liquid and a preparation method and application thereof, wherein the rework liquid comprises an inorganic base, an organic base, a small molecule organic amine, an organic solvent, a corrosion inhibitor and water, and the organic base is 1,8-diazacyclo[5,4,0]undecene-7. The rework liquid of the present invention has high stripping performance and stripping efficiency, and the photoresist can be completely stripped in 1-2 minutes. Moreover, the surface of the stripped substrate after the photoresist is stripped is smooth and has high flatness, and does not affect the repeated use of the thin substrate.

Description

Technical Field

[0001] The invention relates to the technical field of photoresists, and in particular to a CF process negative photoresist reworking liquid and a preparation method and application thereof. Background Art

[0002] Color filter is referred to as CF, and its structure mainly consists of glass substrate, black matrix, color layer, overcoat and ITO conductive film. By controlling the signal processing of IC, the strong light emitted by the backlight source is processed by CF, so that TFT-LCD can be colored. With the development of TFT-LCD, the precision and yield of CF process technology are required to be higher. However, in the CF process, it is inevitable that there will be undesirable phenomena, such as mura defects, light leakage, foreign matter, color unevenness, etc., and after going through BM process, color photoresist coating, exposure, development, baking and other steps, it is impossible to remove only the wrong part. At this time, the color photoresist and overcoat on the problematic CF substrate can only be stripped with rework fluid, so that it can be recycled as a glass substrate to reduce production costs.

[0003] Technical problems of existing rework fluid: The red, green and blue negative photoresists used in the color layer in the CF manufacturing process are more difficult to strip than the positive photoresists, and after exposure, the resin in the negative photoresists undergoes cross-linking reaction and solidification, which increases the difficulty of stripping. The current rework fluid generally has poor stripping effect. CN111638632A discloses a CF process photoresist rework fluid composition, in which the inorganic alkali content is relatively high. After the photoresist is stripped, the surface of the glass and metal layers is rough, which affects the repeated use of the glass substrate. Summary of the invention

[0004] In view of this, the present invention proposes a CF process negative photoresist rework liquid which has good stripping ability for negative photoresist, and at the same time has a smooth surface of the stripped substrate after stripping, is non-corrosive to the glass substrate, and does not affect the repeated use of the glass substrate.

[0005] The technical solution of the present invention is implemented as follows: First, the present invention provides a CF process negative photoresist rework liquid, the rework liquid includes an inorganic base, an organic base, a small molecule organic amine, an organic solvent, a corrosion inhibitor and water, and the organic base is 1,8-diazacyclo[5,4,0]undecene-7.

[0006] On the basis of the above technical scheme, preferably, calculated based on the mass percentage of 100%, the reworking liquid includes 5-10% inorganic base, 5-10% organic base, 25-30% organic solvent, 5-10% small molecule organic amine, 0.05-0.3% corrosion inhibitor, and the balance is water.

[0007] On the basis of the above technical solution, preferably, it further comprises an amide surfactant, and the mass percentage of the amide surfactant is 0.1-0.3%.

[0008] On the basis of the above technical scheme, preferably, the amide surfactant is one or more combinations of potassium cocamide glycinate, sodium cocamide glycinate and cocamidopropyl betaine.

[0009] On the basis of the above technical solution, preferably, the small molecule organic amine is one or more combinations of 1,2-cyclohexanediamine, dimethylamine and diethylamine.

[0010] On the basis of the above technical solution, preferably, the inorganic base is one or more combinations of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate and sodium bicarbonate.

[0011] On the basis of the above technical solution, preferably, the organic solvent is one or more combinations of ethanol, ethyl acetate, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide and diethylene glycol butyl ether.

[0012] On the basis of the above technical solution, preferably, the corrosion inhibitor is one or a combination of two of sodium citrate and sodium hexametaphosphate.

[0013] Second, the present invention provides a method for preparing a negative photoresist rework liquid for a CF process, the method for preparing the rework liquid comprising: adding an inorganic base, an organic solvent, a small molecule organic amine and a corrosion inhibitor into water to form a uniform system at a stirring speed of 500 rpm, and then adding an amide surfactant and an organic base into the system in sequence while stirring to obtain a uniform and stable rework liquid.

[0014] Third, the present invention provides an application of a negative photoresist rework solution for a CF process, comprising the following steps:

[0015] S1, immersing the color filter glass substrate coated with BM, GGB, OC and PS glue in a rework solution at 40-60°C for 1-2 minutes to strip the photoresist;

[0016] S2, taking out the color filter glass substrate after the treatment in step S1, washing it with deionized water, and drying it with nitrogen.

[0017] The CF process negative photoresist rework solution and its preparation method and application of the present invention have the following beneficial effects compared with the prior art:

[0018] (1) The inorganic base and organic base in the rework liquid of the present invention are used as the main stripping components of the rework liquid. The strong stripping ability of 1,8-diazacyclo[5,4,0]undecene-7 on the cured photoresist is utilized to improve the stripping performance and stripping efficiency of the liquid. At the same time, 1,8-diazacyclo[5,4,0]undecene-7 has low corrosiveness to glass. The high chemical activity of small molecule organic amine is conducive to cutting off the cross-linked network of the negative photoresist after curing, and cooperates with the inorganic base and the organic base to strip the cured negative photoresist. The polar organic solvent can dissolve the stripped photoresist to avoid photoresist residue.

[0019] (2) The amide surfactant in the rework solution of the present invention has high water solubility and surface activity, can improve the stability of the overall solution, and can also stably exist in high alkalinity solutions without salting out. Unlike other types of surfactants, amide surfactants have amide groups, and surfactant molecules are more likely to improve the wettability to the substrate, the stability of the solution, and the biodegradability through intermolecular hydrogen bonds or dipole moment interactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a microscopic image of the stripping performance of the reworking fluid of the present invention;

[0022] Figure 2 is the peeling performance contact angle of the reworking fluid of the present invention;

[0023] Figure 3 is the glass roughness of the reworking fluid of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] The CF process negative photoresist rework liquid of this embodiment is calculated based on the mass percentage of 100%, including 2% potassium hydroxide, 3% sodium hydroxide, 75% 1,8-diazacyclo[5,4,0]undecene, 15% ethanol, 15% ethyl acetate, 2% 1,2-cyclohexanediamine, 3% dimethylamine, 0.02% sodium citrate, 0.03% sodium hexametaphosphate, 0.1% potassium cocamide glycinate, and the balance is water.

[0027] Example 2

[0028] The CF process negative photoresist rework liquid of this embodiment includes 3% potassium hydroxide, 3% sodium carbonate, 76% 1,8-diazacyclo[5,4,0]undecene, 13% dimethyl sulfoxide, 13% N-methylpyrrolidone, 3% dimethylamine, 3% diethylamine, 0.05% sodium citrate, 0.05% sodium hexametaphosphate, 0.1% potassium cocamide glycinate, 0.05% sodium cocamide glycinate, and the balance is water.

[0029] Example 3

[0030] The CF process negative photoresist rework liquid of this embodiment includes 3% potassium hydroxide, 4% potassium carbonate, 77% 1,8-diazacyclo[5,4,0]undecene-, 12% N-methylpyrrolidone, 15% N,N-dimethylformamide, 1% 1,2-cyclohexanediamine, 6% dimethylamine, 0.1% sodium citrate, 0.05% sodium hexametaphosphate, 0.1% potassium cocamide glycinate, 0.1% cocoamidopropyl betaine, and the balance is water.

[0031] Example 4

[0032] The CF process negative photoresist rework liquid of this embodiment includes 2% potassium carbonate, 6% sodium bicarbonate, 78% 1,8-diazacyclo[5,4,0]undecene-7, 8% ethanol, 7% dimethyl sulfoxide, 13% N,N-dimethylformamide, 1% 1,2-cyclohexanediamine, 2% dimethylamine, 4% diethylamine, 0.2% sodium citrate, 0.05% potassium cocamide glycinate, 2% sodium cocamide glycinate, and the balance is water.

[0033] Example 5

[0034] The CF process negative photoresist rework liquid of this embodiment includes 5% potassium hydroxide, 4% sodium bicarbonate, 79% 1,8-diazacyclo[5,4,0]undecene-79%, 14% dimethyl sulfoxide, 15% N-methylpyrrolidone, 3% 1,2-cyclohexanediamine, 3% dimethylamine, 3% diethylamine, 0.2% sodium citrate, 0.05% sodium hexametaphosphate, 0.1% potassium cocamide glycinate, 0.1% sodium cocamide glycinate, 0.1% cocamidopropyl betaine, and the balance is water.

[0035] Example 6

[0036] The CF process negative photoresist rework liquid of this embodiment includes 4% sodium hydroxide, 6% sodium bicarbonate, 10% 1,8-diazacyclo[5,4,0]undecene-7, 10% dimethyl sulfoxide, 10% N-methylpyrrolidone, 10% diethylene glycol butyl ether, 3% 1,2-cyclohexanediamine, 2% dimethylamine, 5% diethylamine, 0.1% sodium citrate, 0.2% sodium hexametaphosphate, 0.1% potassium cocamide glycinate, 0.1% sodium cocamide glycinate, 0.1% cocamidopropyl betaine, and the balance is water.

[0037] Example 7

[0038] The CF process negative photoresist rework liquid of this embodiment is calculated based on the mass percentage of 100%, including 3% sodium hydroxide, 4% sodium carbonate, 75% 1,8-diazacyclo[5,4,0]undecene, 10% N-methylpyrrolidone, 10% N,N-dimethylformamide, 10% diethylene glycol butyl ether, 2% 1,2-cyclohexanediamine, 2% dimethylamine, 2% diethylamine, 0.1% sodium citrate, 0.1% sodium hexametaphosphate, 0.5% potassium cocamide glycinate, 0.1% sodium cocamide glycinate, and the balance is water.

[0039] Example 8

[0040] The CF process negative photoresist rework liquid of this embodiment, calculated based on the mass percentage of 100%, includes 2% sodium hydroxide, 2% sodium carbonate, 2% sodium bicarbonate, 78% 1,8-diazacyclo[5,4,0]undecene, 10% ethanol, 8% dimethylacetamide, 10% diethylene glycol butyl ether, 5% 1,2-cyclohexanediamine, 1% dimethylamine, 2% diethylamine, 0.3% sodium citrate, 0.3% potassium cocamide glycinate, and the balance is water.

[0041] Example 9

[0042] The CF process negative photoresist rework liquid of this embodiment includes 5% potassium hydroxide, 2% potassium carbonate, 79% 1,8-diazacyclo[5,4,0]undecene, 18% N-methylpyrrolidone, 9% diethylene glycol butyl ether, 3% dimethylamine, 4% diethylamine, 0.1% sodium citrate, 0.05% potassium cocamide glycinate, 0.1% sodium cocamide glycinate, and the balance is water.

[0043] Comparative Example 1

[0044] Comparative Example 1 is Example 6 lacking the organic base, the inorganic base content is 20%, and the rest is the same as Example 6.

[0045] The CF process negative photoresist rework liquid of this embodiment is calculated based on the mass percentage of 100%, including 8% sodium hydroxide, 12% sodium bicarbonate, 10% dimethyl sulfoxide, 10% N-methyl pyrrolidone, 10% diethylene glycol butyl ether, 3% 1,2-cyclohexanediamine, 2% dimethylamine, 5% diethylamine, 0.1% sodium citrate, 0.2% sodium hexametaphosphate, 0.1% potassium cocamide glycinate, 0.1% sodium cocamide glycinate, 0.1% cocamidopropyl betaine, and the balance is water.

[0046] Comparative Example 2

[0047] Comparative Example 2 is Example 6 which lacks an organic base and an amide surfactant, wherein the content of the inorganic base is 20%, the surfactant is selected from fatty acid hydroxyethane sulfonate, and the rest is the same as Example 6.

[0048] The CF process negative photoresist rework liquid of this embodiment is calculated based on the mass percentage of 100%, including 8% sodium hydroxide, 12% sodium bicarbonate, 3% 1,2-cyclohexanediamine, 2% dimethylamine, 5% diethylamine, 10% dimethyl sulfoxide, 10% N-methylpyrrolidone, 10% diethylene glycol butyl ether, 0.1% sodium citrate, 0.2% sodium hexametaphosphate, 0.3% fatty acid hydroxyethane sulfonate, and the balance is water.

[0049] Comparative Example 3

[0050] Take Example 3 of CN111638632A as Comparative Example 3.

[0051] The preparation method of the rework fluid of the above-mentioned embodiments and comparative examples is: adding inorganic base, organic solvent, small molecule organic amine and corrosion inhibitor into water to form a uniform system at a stirring speed of 500 rpm, and then adding amide surfactant and organic base into the system in sequence while stirring to obtain a uniform and stable rework fluid.

[0052] The application method of the above-mentioned CF process negative photoresist rework liquid is: immerse the color filter glass substrate coated with BM, GGB, OC and PS glue in the above-mentioned rework liquid at 40-60°C for 1-2 minutes to strip off the photoresist; take out the treated color filter glass substrate, wash it with deionized water, and blow it dry with nitrogen.

[0053] The stripping performance and the corrosion to the glass substrate of the rework liquid of the above-mentioned Examples 1-9 and Comparative Examples 1-3 were tested. The results are shown in Tables 1 and Figure 1-3 , Figure 1-2 In the figure, serial numbers 1-9 correspond to the results of embodiments 1-9, and serial numbers 10-12 correspond to the results of corresponding examples 1-3, respectively.

[0054] Table 1 Comparison of rework fluid performance

[0055]

[0056] After stripping for 90 seconds at 60°C, comparative examples 1 and 2 had residual photoresist. Even if the stripping time was extended to 5 minutes, the residual photoresist still could not be stripped, indicating that the photoresist stripping ability of the rework solution with only inorganic base was poor and could not completely strip the photoresist. This also proved the ability of the organic base of the present invention to synergistically strip the photoresist with the inorganic base and the small molecule amine.

[0057] As shown in Table 1: It can be seen from the data of Examples 1-9 that the high-efficiency stripping ability of organic bases and small molecule amines on the cured negative photoresist improves the stripping performance of the solution, and the stability and long-term effectiveness of the solution are improved by the amide surfactants. As shown in the data of Comparative Example 2, in the high-alkali rework solution lacking amide surfactants, the uniformity of the solution is poor when stored at room temperature, and salting out and separation occur; thereby affecting the stripping effect of the photoresist. At the same time, the high-alkali rework solution will also corrode the glass substrate, increasing the roughness of the stripped substrate. The glass of Comparative Example 3 requires 5 minutes to completely strip, while the present application only requires 90 seconds at 60°C, which shows that the stripping efficiency of the rework solution of the present invention is relatively high; although the glass substrate of Comparative Example 3 is not corroded, its surface roughness is relatively large, and it is easy to corrode when repeatedly used, affecting the effect of repeated use.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A CF process negative photoresist rework solution, characterized in that: The rework fluid comprises an inorganic base, an organic base, a small molecule organic amine, an organic solvent, a corrosion inhibitor and water, wherein the organic base is 1,8-diazacyclo[5,4,0]undecene-7; Calculated based on the mass percentage of 100%, the rework fluid includes 5-10% inorganic base, 5-10% organic base, 25-30% organic solvent, 5-10% small molecule organic amine, 0.05-0.3% corrosion inhibitor, and the balance is water; It also includes amide surfactants, the mass percentage of amide surfactants is 0.1-0.3%; The amide surfactant is one or more combinations of potassium cocamide glycinate, sodium cocamide glycinate and cocamidopropyl betaine; The small molecule organic amine is one or more combinations of 1,2-cyclohexanediamine, dimethylamine and diethylamine; The inorganic base is one or more combinations of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate and sodium bicarbonate.

2. A CF process negative photoresist rework solution as claimed in claim 1, characterized in that: The organic solvent is one or more combinations of ethanol, ethyl acetate, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide and diethylene glycol butyl ether.

3. A CF process negative photoresist rework solution as claimed in claim 1, characterized in that: The corrosion inhibitor is one or a combination of sodium citrate and sodium hexametaphosphate.

4. The method for preparing a CF process negative photoresist rework solution as claimed in claim 1, characterized in that: The method comprises the following steps: adding an inorganic base, an organic solvent, a small molecule organic amine and a corrosion inhibitor into water to form a uniform system at a stirring speed of 500 rpm, and then adding an amide surfactant and an organic base into the system in sequence while stirring to obtain a uniform and stable reworking liquid.

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