Photoresist stripping liquid for OLED (Organic Light Emitting Diode) as well as preparation method and application of photoresist stripping liquid

Abstract

The invention belongs to the technical field of etching liquid, and particularly relates to photoresist stripping liquid for an OLED (Organic Light Emitting Diode) as well as a preparation method and application of the photoresist stripping liquid. The photoresist stripping liquid is prepared from the following components in percentage by mass: 1 to 10 percent of organic alcohol amine, 2 to 5 percent of amidino compound, 0.1 to 3 percent of polyhydric alcohol, 0.01 to 0.2 percent of betaine type corrosion inhibitor and the balance of organic solvent, wherein the total mass of the formula is 100 percent. The photoresist stripping liquid for the OLED is excellent in stripping performance and has a good protection effect on an Al layer. The photoresist stripping liquid is especially suitable for the stripping requirement of an OLED device containing Al, can safely strip the cured cross-linked carbonized photoresist, protects the Al process in the OLED device from being corroded, and has a relatively good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of etching solution, and particularly relates to a photoresist stripping solution for OLEDs, a preparation method and application thereof. BACKGROUND

[0002] In OLED display material manufacturing, the photoetching-etching process is a core link for realizing precise pattern transfer, and dry etching is widely applied due to high-precision advantages. The technology completes etching through physical bombardment and chemical reaction of plasma, and transfers the photoresist pattern to the substrate. However, ions and free radicals of the plasma etching gas can cause cross-linking and carbonization of the photoresist, forming a dense and hard modified surface layer, and significantly enhancing the chemical inertness thereof. Traditional photoresist stripping solutions of organic amine and hydroxylamine types are difficult to penetrate the surface layer and destroy the cross-linking structure, resulting in photoresist residues, which seriously affects product yield, and if components with strong cross-linking destruction are used, the organic layer of the OLED device may be degraded, causing irreversible damage.

[0003] Patent CN120276223A discloses a photoresist stripping solution composition and application, and the formula mainly includes alcohol ether solvents, polyol solvents, alkanolamine compounds, metal corrosion inhibitors, surfactants and auxiliary additives. The patent uses alcohol ether solvents and polyol solvents as mixed solvents, which is beneficial to improving the solubility of the stripping solution to the photoresist and prolonging the service life of the stripping solution, but for deeply solidified photoresist, it is difficult to strip and dissolve the photoresist only by relying on alcohol ether solvents and polyol solvents, which still causes the phenomenon of photoresist residues.

[0004] Patent CN120065657A discloses a low-corrosion alkaline photoresist stripping solution, a preparation method and application thereof, which includes 0.1-5 parts of metal protective agent, 5-25 parts of organic alkali, 10-40 parts of polar solvent, 15-45 parts of ultrapure water, and the metal protective agent includes water-soluble carbon dots and alkyl phosphate. The photoresist stripping solution can form a molecular adsorption layer on the copper and Mo / Cu alloy layer to inhibit the corrosion of the metal, but for OLED edge line lapping requiring Al process, part of the Al region is exposed; the stripping solution can corrode Al and the surface oxide layer thereof, and even if the corrosion inhibitor is added, the protection effect on the high-precision Al structure is still insufficient.

[0005] It is necessary to provide a new photoresist stripping solution for OLEDs to realize efficient stripping and reduce corrosion on the OLED device, especially the Al region. SUMMARY

[0006] To solve the above technical problems, the application first provides a photoresist stripping solution for OLEDs.

[0007] The technical scheme adopted by the application is as follows: An OLED photoresist stripping liquid, comprising, based on the total mass of the formula being 100%, 1-10% of an organic alcohol amine, 2-5% of an amidino compound, 0.1-3% of a polyol, 0.01-0.2% of a betaine type corrosion inhibitor, and the rest being an organic solvent.

[0008] Preferably, the organic alcohol amine is any one or a combination of multiple of ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, 3-amino-1-propanol, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, diglycolamine, triglycolamine. The amount of the organic alcohol amine includes but is not limited to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%.

[0009] Preferably, the amidino compound is any one or a combination of multiple of N'-hydroxy-1H-indole-3-carboxamidine, N-[3-(aminomethyl)benzyl]acetamidine, N'-hydroxy-2-naphthylacetamidine, 2-(2-thienyl)hydroxyacetamidine, 4-methylsulfonylbenzamidine, 4-benzylpiperazine-1-carboxamidine. The amount of the amidino compound includes but is not limited to 2%, 2.2%, 2.5%, 2.8%, 3%, 3.5%, 4%, 4.3%, 4.7%, 5%.

[0010] Preferably, the polyol is composed of a small molecule polyol and a large molecule polyol in a mass ratio of 3: (1-2). The amount of the polyol includes but is not limited to 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.6%, 1.9%, 2%, 2.2%, 2.5%, 2.8%, 3%.

[0011] Preferably, the small molecule polyol is any one or a combination of multiple of glycerol, ethylene glycol, triethylene glycol, sorbitol, xylitol, erythritol.

[0012] Preferably, the large molecule polyol is polypropylene glycol or polyethylene glycol, which has a single average molecular weight in the range of 400-2000 Da. Further, the large molecule polyol is any one or a combination of multiple of PPG-400, PPG-1000, PPG-2000, PEG-400, PEG-1000, PEG-2000.

[0013] Preferably, the betaine type corrosion inhibitor is any one or a combination of multiple of a pyridine betaine, a piperazine betaine, an imidazoline betaine, an amide betaine. The amount of the betaine type corrosion inhibitor includes but is not limited to 0.01%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%.

[0014] Preferably, the pyridine betaine is 1-(3-thiopropyl)-2-vinylpyridine betaine; the piperazine betaine is 1,4-dimethylpiperazine dibetaine; the imidazoline betaine is lauryl imidazoline betaine or hydroxyethyl oleic acid imidazoline betaine; and the amide betaine is oleic acid amamidopropyl betaine.

[0015] Preferably, the organic solvent is any one or a combination of N-methylformamide, N-methylpyrrolidone, N,N-dimethylformamide, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and dimethyl sulfoxide.

[0016] The present invention further provides a method for preparing a photoresist stripping solution for OLEDs as described above, wherein the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor are added to an organic solvent, the system is heated to 40~50°C, and stirred for 5~10 min to obtain the photoresist stripping solution for OLEDs.

[0017] Preferably, a filtration process is performed after stirring to remove any undissolved solids that may be present.

[0018] Finally, this invention provides the application of the OLED photoresist stripping solution described above in the stripping of photoresist from the surface of aluminum-containing OLED devices.

[0019] The beneficial effects of this invention are as follows: Aluminum processing is the foundation of OLED device industrialization, and photoresist is essential for patterning aluminum processes. Polymer photoresist bonds tightly to the aluminum surface oxide film, and after dry etching, it undergoes cross-linking and carbonization to form a dense layer. This double barrier prevents the penetration of stripping solution, meaning that even high-concentration and long-term treatment with traditional stripping solutions cannot completely remove the aluminum. In fact, this process can cause irreversible corrosion to the aluminum process.

[0020] This invention improves upon existing stripping solution formulations. In the photoresist stripping solution formulation of this invention: 1) Organic solvents can rapidly penetrate the intermolecular gaps, weakening the intermolecular forces of polymer chains, causing the photoresist to swell and soften, while simultaneously initially dissolving incompletely cross-linked small molecule fragments, reducing the adhesion between the photoresist and the OLED substrate. 2) The amino groups of organic alcohol amines can decompose the stable long chains of the photoresist into small molecule residues easily soluble in the stripping solution. 3) The amidine compounds can interact with the active sites of the photoresist through aromatic rings, hydroxyl groups, and other groups in their molecular structure, enabling the strongly nucleophilic amidine groups to selectively break the dense cross-linked bonds formed after dry etching of the photoresist, disrupting the stable structure of the carbonized layer, degrading the insoluble photoresist into soluble small molecules, and achieving efficient photoresist stripping. 4) The polyol is composed of small-molecule polyol and large-molecule polyol in a set ratio. Due to its small molecular size and good fluidity, the small-molecule polyol can penetrate into the gaps of the photoresist along with the organic solvent. Its hydroxyl groups can form hydrogen bonds with the degradation residue, improving the solubility of the residue and avoiding stripping residue. The large-molecule polyol can adjust the viscosity of the stripping solution, allowing the stripping solution to fully interact with the photoresist and enhancing wettability, promoting the removal of residue from the substrate and preventing secondary adhesion. The two are compounded in a specific ratio to ensure that the dissolved residue can be smoothly removed from the substrate. 5) The betaine-type corrosion inhibitor has both cationic quaternary ammonium groups and anionic polar groups such as pyridyl groups. Its quaternary ammonium cations can generate physical adsorption at the negative potential points on the aluminum surface, and the polar groups can form coordination bonds with aluminum ions to achieve chemical adsorption. The dense film formed by the dual adsorption can isolate the alkaline components of the stripping solution from the aluminum substrate and hinder the dissolution of aluminum. In addition, the small-molecule polyol in the formula can also fill the tiny gaps in the protective film, improve the film density, and further reduce the erosion of the aluminum surface by the stripping solution.

[0021] The photoresist stripping solution prepared in this invention exhibits excellent stripping performance, rapidly penetrating and disrupting the cross-linked structure of the photoresist, degrading it into easily soluble small molecules. Test results show that no photoresist residue remains after stripping, and very little photoresist residue is present in the stripping solution. The photoresist stripping solution also provides good protection for the Al layer; test results show that the sample exhibits no "layering and suspension" phenomenon after stripping, with the lowest Al leaching amount being only 0.41 ppb, exhibiting almost no corrosion. This photoresist stripping solution is particularly suitable for the stripping requirements of Al-containing OLED devices, safely stripping the cured, cross-linked, and carbonized photoresist while protecting the aluminum-based processes in OLED devices from corrosion, demonstrating promising application prospects. Attached Figure Description

[0022] Figure 1 This is an optical microscope (OM) image of the test sample plane before peeling (100x magnification).

[0023] Figure 2 The planar OM image (magnified 100x) of the sample after being stripped with the photoresist stripping solution prepared in Example 1.

[0024] Figure 3 The planar OM image (magnified 100x) of the sample after being stripped with the photoresist stripping solution prepared in Comparative Example 1.

[0025] Figure 4 The planar OM image (magnified 100x) of the sample after being stripped with the photoresist stripping solution prepared in Comparative Example 2.

[0026] Figure 5 This is a focused ion beam (FIB) image of the cross-section of the test sample before peeling.

[0027] Figure 6 The image shows a cross-sectional FIB diagram of the sample after being stripped with the photoresist stripping solution prepared in Example 1.

[0028] Figure 7 The image shows a cross-sectional FIB diagram of the sample after being stripped with the photoresist stripping solution prepared in Comparative Example 1.

[0029] Figure 8 The image shows a cross-sectional FIB diagram of the sample after being stripped with the photoresist stripping solution prepared in Comparative Example 4. Detailed Implementation

[0030] To facilitate understanding, the technical solution of the present invention will be described in more detail below with reference to embodiments. Unless otherwise stated, the terms used herein have the meanings conventionally understood by those skilled in the art.

[0031] Example 1 An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 10% organic alcohol amine, 2% amidine compound, 0.1% polyol, 0.01% betaine-type etching inhibitor, and the remainder being organic solvent. The polyol is composed of a small-molecule polyol and a large-molecule polyol in a mass ratio of 3:1.

[0032] Specifically, the organic solvent is composed of N,N-dimethylformamide and diethylene glycol monomethyl ether in a mass ratio of 1:1; the organic alcohol amine is composed of ethanolamine and triethylene glycolamine in a mass ratio of 1:1; the small molecule polyol is ethylene glycol; the large molecule polyol is PPG-400; the amidine compound is 2-(2-thienyl)hydroxyacetamidine; and the betaine-type corrosion inhibitor is 1-(3-thiopropyl)-2-vinylpyridine betaine.

[0033] The preparation method of the photoresist stripping solution for OLED is as follows: add the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 40°C, stir for 10 min, and then filter to remove undissolved solids to obtain the solution.

[0034] Example 2 An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 5% organic alcohol amine, 3% amidine compound, 1.5% polyol, 0.1% betaine-type etching inhibitor, and the remainder being organic solvent. The polyol is composed of a small-molecule polyol and a large-molecule polyol in a mass ratio of 2:1.

[0035] Specifically, the organic solvent is composed of N-methylformamide and dimethyl sulfoxide in a mass ratio of 2:1; the organic alcohol amine is composed of ethanolamine and diethylene glycolamine in a mass ratio of 1:2; the small molecule polyol is sorbitol; the large molecule polyol is PEG-400; the amidine compound is N'-hydroxy-1H-indole-3-formamidinium; and the betaine-type corrosion inhibitor is lauryl imidazoline betaine.

[0036] The preparation method of the photoresist stripping solution for OLED is as follows: add the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 50°C, stir for 5 minutes, and then filter to remove undissolved solids to obtain the solution.

[0037] Example 3 An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 1% organic alcohol amine, 5% amidine compound, 3% polyol, 0.2% betaine-type etching inhibitor, and the remainder being organic solvent. The polyol is composed of a small-molecule polyol and a large-molecule polyol in a mass ratio of 3:2.

[0038] Specifically, the organic solvent is composed of N,N-dimethylformamide, diethylene glycol monomethyl ether, and dimethyl sulfoxide in a mass ratio of 1:1:1; the organic alcohol amine is composed of 3-amino-1-propanol and N,N-dimethylethanolamine in a mass ratio of 1:1; the small molecule polyol is xylitol; the large molecule polyol is composed of PPG-400 and PEG-2000 in a mass ratio of 1:1; the amidine compound is 4-methyl sulfone benzidine; and the betaine-type corrosion inhibitor is oleamidopropyl betaine.

[0039] The preparation method of the photoresist stripping solution for OLED is as follows: add the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 45°C, stir for 8 min, and then filter to remove undissolved solids to obtain the solution.

[0040] Comparative Example 1 An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 10% organic alcohol amine, 2% amidine compound, 0.1% polyol, 0.01% betaine-type etching inhibitor, and the remainder being organic solvents. The polyol is only a small molecule polyol.

[0041] Specifically, the organic solvent is composed of N,N-dimethylformamide and diethylene glycol monomethyl ether in a mass ratio of 1:1; the organic alcohol amine is composed of ethanolamine and triethylene glycolamine in a mass ratio of 1:1; the small molecule polyol is ethylene glycol; the amidine compound is 2-(2-thienyl)hydroxyacetamidine; and the betaine-type corrosion inhibitor is 1-(3-thiopropyl)-2-vinylpyridine betaine.

[0042] The preparation method of the photoresist stripping solution for OLED is as follows: add the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 50°C, stir for 5 min, and then filter to remove undissolved solids to obtain the solution.

[0043] Comparative Example 2

[0044] An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 10% organic alcohol amine, 2% amidine compound, 0.1% polyol, 0.01% betaine-type etching inhibitor, and the remainder being organic solvents. The polyol is only a large-molecule polyol.

[0045] Specifically, the organic solvent is composed of N,N-dimethylformamide and diethylene glycol monomethyl ether in a mass ratio of 1:1; the organic alcohol amine is composed of ethanolamine and triethylene glycolamine in a mass ratio of 1:1; the macromolecular polyol is PPG-400; the amidine compound is 2-(2-thienyl)hydroxyacetamidine; and the betaine-type corrosion inhibitor is 1-(3-thiopropyl)-2-vinylpyridine betaine.

[0046] The preparation method of the photoresist stripping solution for OLED is as follows: add the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 40°C, stir for 10 min, and then filter to remove undissolved solids to obtain the solution.

[0047] Comparative Example 3 An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 10% organic alcohol amine, 2% amidine compound, 0.1% polyol, 0.01% betaine-type etching inhibitor, and the remainder being organic solvent. The polyol is composed of a small-molecule polyol and a large-molecule polyol in a mass ratio of 3:1.

[0048] Specifically, the organic solvent is composed of N,N-dimethylformamide and diethylene glycol monomethyl ether in a mass ratio of 1:1; the organic alcohol amine is composed of ethanolamine and triethylene glycolamine in a mass ratio of 1:1; the small molecule polyol is ethylene glycol; the large molecule polyol is PPG-400; the amidoyl compound is 1,5-diazabicyclo[4.3.0]non-5-ene; and the betaine-type corrosion inhibitor is 1-(3-thiopropyl)-2-vinylpyridine betaine.

[0049] The preparation method of the photoresist stripping solution for OLED is as follows: add the required mass of organic alcohol amine, amidine compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 40°C, stir for 10 min, and then filter to remove undissolved solids to obtain the solution.

[0050] Comparative Example 4 An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 10% organic alcohol amine, 2% amidine compound, 0.1% polyol, 0.01% 1,2,3-benzotriazole, and the remainder being organic solvent. The polyol is composed of a small-molecule polyol and a large-molecule polyol in a mass ratio of 3:1.

[0051] Specifically, the organic solvent is composed of N,N-dimethylformamide and diethylene glycol monomethyl ether in a mass ratio of 1:1; the organic alcohol amine is composed of ethanolamine and triethylene glycolamine in a mass ratio of 1:1; the small molecule polyol is ethylene glycol; the large molecule polyol is PPG-400; and the amidine compound is 2-(2-thienyl)hydroxyacetamidinium.

[0052] The preparation method of the OLED photoresist stripping solution is as follows: add the required mass of organic alcohol amine, amidoyl compound, polyol and 1,2,3-benzotriazole to an organic solvent, heat the system to 40°C, stir for 10 min, and then filter to remove undissolved solids to obtain the solution.

[0053] Peel test The test samples were Ti-Al-Ti (thickness 180Å-1000Å-180Å, OLED pixel electrode) samples from the OLED manufacturing process to be stripped of photoresist. At 60°C, the samples were clamped and fixed, then immersed in the photoresist stripping solutions prepared in Examples 1-3 and Comparative Examples 1-4, and agitated back and forth for 120 s for stripping. They were then rinsed with ultrapure water for 1 min and finally dried with high-purity nitrogen gas to obtain the samples after photoresist stripping.

[0054] Optical microscope (OM) was used to observe the sample plane to check for photoresist residue. A liquid particle counter was used to detect the number of particles in the stripping solution (particle size greater than 0.5 μm / (pcs / mL)) to assess the photoresist residue in the stripping solution. A focused ion beam microscope (FIB) was used to observe the sample cross-section to evaluate the Al layer corrosion. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to detect aluminum ions in the photoresist stripping solution. The metal ion dissolution amount = metal ion content in the photoresist stripping solution after stripping - metal ion content in the photoresist stripping solution before stripping, thereby evaluating the metal layer corrosion.

[0055] Photoresist residue on the sample: A: No photoresist on the sample; B: Thin residue on the sample; C: Thick residue on the sample. Photoresist residue status in the stripping solution: A: Particle count ≤ 100; B: 100 < Particle count ≤ 300; C: Particle count > 300; Al layer corrosion: Al corrosion occurs along the edge of Al. If the Al layer is corroded, the upper Ti and the lower Ti will exhibit a "layered suspension" phenomenon with respect to the edge of the Al layer. Let Top be the horizontal distance between the upper metal Ti and the middle metal Al, and Bottom be the horizontal distance between the lower metal Ti and the middle metal Al. Then: +++: The Al layer is not corroded (no layered suspension phenomenon occurs); ++: The Al layer has slight corrosion (the values ​​of Top and Bottom are both between 100 and 500 nm); +: The Al layer is corroded (the values ​​of Top and Bottom are both greater than 500 nm).

[0056] See results Figures 1-8 See Table 1. Figure 1 The planar OM diagram of the test sample before peeling (magnified 100 times); Figures 2-4 The images show planar OM (Optical Object Model) images of the samples after being stripped with the photoresist stripping solutions prepared in Example 1, Comparative Example 1, and Comparative Example 2, respectively. Figure 5 This is a cross-sectional FIB diagram of the test sample before peeling. Figures 6-8 The images show cross-sectional FIB diagrams of the samples after being stripped with the photoresist stripping solutions prepared in Example 1, Comparative Example 1, and Comparative Example 4, respectively. Figures 6-8 In the diagram, the data at the top corresponds to the Top value, and the data at the bottom corresponds to the Bottom value.

[0057] Table 1. Test results of different photoresist stripping solutions for OLEDs

[0058] It can be seen that the photoresist stripping solutions prepared in Examples 1-3 can all achieve good stripping effects. There are almost no photoresist residues in the stripping solution after etching, indicating that it dissolves the photoresist well and the Al metal layer is almost uncorroded.

[0059] Combination Figures 1-4 It can be seen that the test sample before peeling ( Figure 1 As can be seen, the photoresist is perfectly coated on the surface of the wire; after being stripped using the photoresist stripping solution prepared in Example 1 ( Figure 2 In Comparative Examples 1 and 2, the photoresist was completely stripped away without any residue, and the conductive lines were fully exposed. However, in Comparative Example 1, only small-molecule polyols were used, without the encapsulating and dispersing effect of large-molecule polyols. As a result, the degraded photoresist fragments rapidly aggregated, forming large, thick residues. Figure 3The area within the box in the image adheres to the surface of the conductor, and the number of large particles in the stripping solution increases dramatically. Comparative Example 2 uses only macromolecular polyols, which have weak penetrating power and cannot assist organic amines and organic solvents in penetrating deep into the adhesive layer, resulting in incomplete degradation of the photoresist and leaving small, thin residues. Figure 4 (The selected area in the image); Conversely, the combination of small-molecule polyols and large-molecule polyols can work synergistically to ensure that the residue does not remain on the sample or accumulate in the stripping solution.

[0060] Compared with Comparative Example 3, the amidine compound in Example 1 is 2-(2-thienyl)hydroxyacetamidine, which can help the amidine group to be located at the active site of the photoresist through hydrogen bonding and π-π stacking, so that the amidine group specifically breaks the dense cross-linking bond of the photoresist, degrading the macromolecular adhesive layer into soluble small molecules; the amidine compound in Comparative Example 3 is 1,5-diazabicyclo[4.3.0]non-5-ene, the cycloamidinium structure can only slightly swell the photoresist and cannot break the cross-linking bond, resulting in incomplete degradation of the adhesive layer and the formation of thick residue. At the same time, 1,5-diazabicyclo[4.3.0]non-5-ene is more basic, resulting in excessively strong alkalinity of the system, causing corrosion of the Al layer.

[0061] Compared with Comparative Example 4, Example 1 uses a betaine-type corrosion inhibitor with a zwitterionic structure to form a dense bilayer through physical and chemical adsorption, which isolates the alkaline components in the stripping solution from contact with the Al layer. Comparative Example 4 uses 1,2,3-benzotriazole, which has poor compatibility with the stripping solution system of the present invention and may have a weak interaction with amidine compounds, further reducing the corrosion inhibition activity and leading to severe corrosion of the Al layer.

[0062] The above test results show that the photoresist stripping solution provided by the present invention has good photoresist dissolving and stripping capabilities, and has a good protective effect on the Al layer, and can be widely used in the field of display panel etching.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photoresist stripping solution for OLEDs, characterized in that, Based on the total mass of the formulation (100%), it includes: 1-10% organic alcohol amines, 2-5% amidine compounds, 0.1-3% polyols, 0.01-0.2% betaine-type corrosion inhibitors, and the remainder being organic solvents.

2. The photoresist stripping solution for OLEDs as described in claim 1, characterized in that, The organic alcohol amine is any one or a combination of multiple of the following: ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, 3-amino-1-propanol, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, diethylene glycolamine, and triethylene glycolamine.

3. The photoresist stripping solution for OLEDs as described in claim 1, characterized in that, The amidoyl compound is any one or a combination of N'-hydroxy-1H-indole-3-formamidine, N-[3-(aminomethyl)benzyl]acetamidine, N'-hydroxy-2-naphthoformamidine, 2-(2-thienyl)hydroxyacetamidine, 4-methylsulfonylbenzamide, and 4-benzylpiperazine-1-carbamate.

4. The photoresist stripping solution for OLEDs as described in claim 1, characterized in that, The polyol is composed of small molecule polyol and large molecule polyol mixed in a mass ratio of 3:(1~2).

5. The photoresist stripping solution for OLEDs as described in claim 4, characterized in that, The small molecule polyol is any one or a combination of glycerol, ethylene glycol, triethylene glycol, sorbitol, xylitol, and erythritol; the macromolecule polyol is polypropylene glycol or polyethylene glycol and has a single average molecular weight in the range of 400 to 2000 Da.

6. The photoresist stripping solution for OLEDs as described in claim 1, characterized in that, The betaine-type corrosion inhibitor is any one or a combination of multiple types of pyridine betaine, piperazine betaine, imidazoline betaine, and amide betaine.

7. The photoresist stripping solution for OLEDs as described in claim 6, characterized in that, The pyridine betaine is 1-(3-thiopropyl)-2-vinylpyridine betaine; the piperazine betaine is 1,4-dimethylpiperazine dibetaine; the imidazoline betaine is lauryl imidazoline betaine or hydroxyethyl oleic acid imidazoline betaine; and the amide betaine is oleic acid amamidopropyl betaine.

8. The photoresist stripping solution for OLEDs as described in claim 1, characterized in that, The organic solvent is any one or a combination of N-methylformamide, N-methylpyrrolidone, N,N-dimethylformamide, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and dimethyl sulfoxide.

9. A method for preparing a photoresist stripping solution for OLEDs as described in any one of claims 1-8, characterized in that, Add the required amount of organic alcohol amine, amidoyl compound, polyol and betaine-type corrosion inhibitor to an organic solvent, heat the system to 40~50℃, stir for 5~10 min, and obtain the photoresist stripping solution for OLED.

10. The application of the OLED photoresist stripping solution as described in any one of claims 1-8 in stripping photoresist from the surface of aluminum-containing OLED devices.

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