A negative photoresist developer for CF process in TFT-LCD industry

Abstract

The present invention belongs to the field of metal etching technology and particularly relates to a negative photoresist developer for the CF process in the TFT-LCD industry. The developer comprises the following components by weight: 5-25wt% inorganic base, 2-10wt% surfactant, 2-10wt% hydrotrope, and the balance deionized water. The surfactant is a mixture of an alkyl sulfate, an alkyl glycoside composition LF-802, and an ethoxylated quaternary ammonium salt composition LF-810 in a mass ratio of 1:1 to 1:2. The negative photoresist developer has the advantages of high dispersion stability, clear patterns after development, no burrs, no photoresist residue, no undercutting, and no anti-sticking of the photoresist at the end of the development process.

Description

Technical Field

[0001] The present invention relates to the technical field of metal etching, and in particular to a negative photoresist developer for a CF process in the TFT-LCD industry. Background Art

[0002] Thin-film transistor liquid crystal displays (TFT-LCDs) have the characteristics of light weight, flatness, low power consumption, no radiation, and excellent display quality. Their application areas are gradually expanding, and have developed from displays for audio-visual products, laptops, etc. to monitors for desktop computers, engineering workstations (ews), and other fields.

[0003] A color filter (CF) is a component in a TFT-LCD assembly. Its primary function is to enable the LCD to produce a color image. In existing color filter manufacturing processes, the developer for the black matrix (BM) and RGB photoresist is primarily an alkaline developer, consisting primarily of a strong base, a surfactant, and deionized water. Initially, this dissolution proceeds smoothly. However, as the dissolved photoresist accumulates in the developer, it forms an emulsion or a highly viscous solution. Insoluble matter gradually forms within the developer, and these residues easily adhere to the substrate or photoresist surface, forming film fouling. In particular, insoluble components such as pigment particles, which have been added to photoresist in recent years to enhance color contrast and saturation in displays, can accumulate and easily re-deposit onto the substrate or photoresist pattern. This can contaminate the CF surface, cause incomplete development, and hinder the formation of accurate photoresist images. Common developers on the market, in addition to performance drawbacks such as excessive foaming, a narrow operating range, and residual residue after development, also suffer from low developer concentrations, frequent procurement, and high costs.

[0004] Therefore, the present invention provides a new negative photoresist developer formula to solve the above problems. Summary of the Invention

[0005] The main purpose of the present invention is to provide a negative photoresist developer for the CF process in the TFT-LCD industry, which has better comprehensive performance.

[0006] The present invention achieves the above-mentioned object through the following technical solution: a negative photoresist developer for the CF process in the TFT-LCD industry, comprising the following components in percentage by weight: 5-25wt% of an inorganic base, 2-10wt% of a surfactant, 2-10wt% of a hydrotrope, and the balance deionized water, wherein the surfactant is a mixture of LF-802 and LF-810 in a mass ratio of 1:1 to 1:2, the LF-802 is a combination of an alkyl sulfate and an alkyl glycoside, and the LF-810 is a combination of an anionic nonionic surfactant and an ethoxylated quaternary ammonium salt.

[0007] Specifically, the inorganic base is preferably potassium hydroxide, sodium hydroxide, sodium bicarbonate or sodium carbonate.

[0008] Specifically, the hydrotrope includes at least one of sodium toluenesulfonate, sodium xylenesulfonate, sodium isopropylsulfonate, sodium p-methylisopropylsulfonate, sodium 1-hydroxy-2-naphthoate, sodium 2-hydroxy-1-1 naphthalenesulfonate, and sodium 2-ethylhexyl sulfate.

[0009] The beneficial effects of the present invention are:

[0010] The negative photoresist developer of the present invention has the characteristics of high dispersion stability, clear pattern after development, no burrs, no photoresist residue, no undercut, and no anti-sticking of the final photoresist. DETAILED DESCRIPTION

[0011] A negative photoresist developer for the CF process in the TFT-LCD industry is composed of the following components in percentage by weight: 5-25wt% of an inorganic base, 2-10wt% of a surfactant, 2-10wt% of a hydrotrope, and the balance deionized water. The surfactant is a mixture of LF-802 and LF-810 in a mass ratio of 1:1 to 1:2. The LF-802 is a combination of an alkyl sulfate and an alkyl glycoside, and the LF-810 is a combination of an anionic nonionic surfactant and an ethoxylated quaternary ammonium salt.

[0012] Inorganic bases are generally strong bases, which are used to break down the polymer chains in the photoresist into small molecular structures.

[0013] Special surfactants make it easier for the developer to penetrate and dissolve the photoresist.

[0014] Hydrotropes can improve the properties of surfactants in the product, increase the solubility limit of the photoresist in the system, and ensure the service life of the product.

[0015] Deionized water is preferably 18 MΩ·cm ultrapure water.

[0016] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0017] Examples 1-7:

[0018] The negative photoresist developer for the CF process in the TFT-LCD industry of Examples 1-7 was prepared by mixing according to the formula in Table 1:

[0019] Table 1: Unit: wt%

[0020]

[0021] Note: ① The content less than 100wt% is supplemented by deionized water;

[0022] ② In surfactant, A refers to LF-802, and B refers to LF-810.

[0023] A comparative experiment was conducted using the developer described in CN103955121A as control example 1 and the developer composition described in CN108027569A as control example 2.

[0024] Experimental method:

[0025] Dilute the developer composition 100-500 times with 18 MΩ·cm ultrapure water. Maintain the temperature at 25°C and spray the diluted developer onto the photoresist test wafer at a constant pressure for 60 seconds. Rinse with 18 MΩ·cm ultrapure water and dry with nitrogen. Observe the developed pattern under a metallographic microscope for clarity, burrs on the edges, the presence of photoresist residue, and any signs of underdevelopment or overdevelopment. After development, the test wafer is cracked and the cross-sectional morphology of the developed photoresist is examined under a scanning electron microscope (SEM) to examine the smoothness of the photoresist edges, the presence of undercuts, and the presence of resist back-tack at the end.

[0026] Table 2:

[0027]

[0028] As shown in Table 2, compared with the control examples 1-2, the negative photoresist developers of Examples 1-7 have the characteristics of high dispersion stability, clear patterns after development, no burrs, no photoresist residue, no undercut, and no anti-sticking of the final photoresist.

[0029] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A negative photoresist developer for CF process in TFT-LCD industry, characterized by The invention is composed of the following components in percentage by weight: 5-25wt% of an inorganic base, 2-10wt% of a surfactant, 2-10wt% of a hydrotrope and the balance of deionized water, wherein the surfactant is a mixture of LF-802 and LF-810 in a mass ratio of 1:1 to 1:2, the LF-802 is a composition of an alkyl sulfate and an alkyl glycoside, and the LF-810 is a composition of an anionic nonionic surfactant and an ethoxylated quaternary ammonium salt.

2. The negative photoresist developer for the CF process in the TFT-LCD industry according to claim 1, characterized in that: The inorganic base is preferably potassium hydroxide, sodium hydroxide, sodium bicarbonate or sodium carbonate.

3. The negative photoresist developer for the CF process in the TFT-LCD industry according to claim 1, characterized in that: The hydrotrope includes at least one of sodium toluenesulfonate, sodium xylenesulfonate, sodium isopropylsulfonate, sodium p-methylisopropylsulfonate, sodium 1-hydroxy-2-naphthoate, sodium 2-hydroxy-1-1 naphthalenesulfonate, and sodium 2-ethylhexyl sulfate.

Images