A photoresist stripping solution for OLEDs, and a preparation method and application thereof

Abstract

The application belongs to the technical field of etching liquid, and particularly relates to a photoresist stripping liquid for OLED, a preparation method and application thereof. The photoresist stripping liquid comprises, with the total mass of the formula being 100%, 1-10% of organic alcohol amine, 2-5% of amidino compound, 0.1-3% of polyol, 0.01-0.2% of betaine type corrosion inhibitor, and the rest is organic solvent. The photoresist stripping liquid for OLED has excellent stripping performance and good protection effect on the Al layer. The photoresist stripping liquid is particularly suitable for stripping requirements of OLED devices containing Al, can safely strip the photoresist which is cross-linked and carbonized after solidification, and at the same time protects the Al process in the OLED device from being corroded, and has good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of etching solution technology, specifically relating to a photoresist stripping solution for OLEDs, its preparation method, and its application. Background Technology

[0002] In OLED display material manufacturing, photolithography-etching is the core process for achieving precise pattern transfer, and dry etching is widely used due to its high precision. This technology completes etching through the physical bombardment and chemical reaction of plasma, transferring the photoresist pattern to the substrate. However, the ions and free radicals in the plasma etching gas can cause cross-linking and carbonization of the photoresist, forming a dense and hard modified surface layer, which significantly enhances its chemical inertness. Traditional photoresist stripping solutions such as organic amines and hydroxylamines are difficult to penetrate this surface layer and destroy the cross-linked structure, resulting in photoresist residue and seriously affecting product yield. On the other hand, if components with strong cross-linking destructive effects are used, it may cause degradation of the organic layer of the OLED device, causing irreversible damage.

[0003] Patent CN120276223A discloses a photoresist stripping solution composition and its application. The formulation mainly includes alcohol ether solvents, polyol solvents, alkanolamine compounds, metal corrosion inhibitors, surfactants, and auxiliary additives. This patent utilizes alcohol ether solvents and polyol solvents as a mixed solvent, which is beneficial for improving the stripping solution's ability to dissolve photoresist and extending its lifespan. However, for deeply cured photoresists, relying solely on alcohol ether solvents and polyol solvents is insufficient to strip and dissolve the photoresist, still resulting in residual photoresist.

[0004] Patent CN120065657A discloses a low-corrosion alkaline photoresist stripping solution, its preparation method, and its application. The solution comprises 0.1-5 parts by weight of a metal protectant, 5-25 parts by weight of an organic base, 10-40 parts by weight of a polar solvent, and 15-45 parts by weight of ultrapure water. The metal protectant includes water-soluble carbon dots and alkyl phosphates. This photoresist stripping solution can form a molecular adsorption layer on copper and Mo / Cu alloy layers, inhibiting metal corrosion. However, for OLED edge wiring connections, an Al process is required, resulting in the exposure of some Al areas. Furthermore, this stripping solution corrodes Al and its surface oxide layer; even with the addition of corrosion inhibitors, the protection effect on high-precision Al structures remains insufficient.

[0005] It is essential to provide a new photoresist stripping solution for OLEDs that achieves efficient stripping and reduces corrosion of OLED devices, especially the Al region. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention first provides a photoresist stripping solution for OLEDs.

[0007] The technical solution adopted in this invention is as follows:

[0008] An OLED photoresist stripping solution, based on 100% of the total mass of the formulation, comprises: 1-10% organic alcohol amine, 2-5% amidine compound, 0.1-3% polyol, 0.01-0.2% betaine-type corrosion inhibitor, and the remainder being organic solvent.

[0009] Preferably, the organic alcohol amine is any one or a combination of more 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. The amount of the organic alcohol amine used includes, but is not limited to, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%.

[0010] Preferably, the amidoyl compound is any one or a combination of more of N'-hydroxy-1H-indole-3-formamidinium, N-[3-(aminomethyl)benzyl]acetamidine, N'-hydroxy-2-naphthoformamidinium, 2-(2-thienyl)hydroxyacetamidine, 4-methylsulfonylbenzamide, and 4-benzylpiperazine-1-carbamate. The amount of the amidoyl compound used includes, but is not limited to, 2.2%, 2.5%, 2.8%, 3%, 3.5%, 4%, 4.3%, 4.7%, and 5%.

[0011] Preferably, the polyol is composed of small-molecule polyol and large-molecule polyol mixed in a mass ratio of 3:(1~2). The amount of the polyol used 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%, and 3%.

[0012] Preferably, the small molecule polyol is any one or a combination of multiple of glycerol, ethylene glycol, triethylene glycol, sorbitol, xylitol, and erythritol.

[0013] Preferably, the macromolecular polyol is polypropylene glycol or polyethylene glycol, having a single average molecular weight in the range of 400-2000 Da. Further, the macromolecular polyol is any one or a combination of multiples of PPG-400, PPG-1000, PPG-2000, PEG-400, PEG-1000, and PEG-2000.

[0014] Preferably, the betaine-type corrosion inhibitor is any one or a combination of multiple betaines selected from pyridine betaines, piperazine betaines, imidazoline betaines, and amide betaines. The dosage 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%, and 0.2%.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] Preferably, a filtration process is performed after stirring to remove any undissolved solids that may be present.

[0019] 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.

[0020] The beneficial effects of this invention are as follows:

[0021] 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.

[0022] 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.

[0023] 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

[0024] Figure 1 This is an optical microscope (OM) image of the test sample plane before peeling (100x magnification).

[0025] Figure 2 The planar OM image (magnified 100x) of the sample after being stripped with the photoresist stripping solution prepared in Example 1.

[0026] Figure 3 The image shows a planar OM (magnified 100x) image of the sample after being stripped with the photoresist stripping solution prepared in Comparative Example 1.

[0027] Figure 4 The planar OM image (magnified 100x) of the sample after being stripped with the photoresist stripping solution prepared in Comparative Example 2.

[0028] Figure 5 This is a focused ion beam (FIB) image of the cross-section of the test sample before peeling.

[0029] 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.

[0030] Figure 7 The image shows a cross-sectional FIB diagram of the sample after it has been stripped with the photoresist stripping solution prepared in Comparative Example 1.

[0031] 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

[0032] 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.

[0033] Example 1

[0034] 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.

[0035] 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.

[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 40°C, stir for 10 min, and then filter to remove undissolved solids to obtain the solution.

[0037] Example 2

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Example 3

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Comparative Example 1

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Comparative Example 2

[0050] 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.

[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 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.

[0052] 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.

[0053] Comparative Example 3

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Comparative Example 4

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Peel test

[0062] 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.

[0063] 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.

[0064] Photoresist residue on the sample: A: No photoresist on the sample; B: Thin residue on the sample; C: Thick residue on the sample.

[0065] Photoresist residue status in the stripping solution: A: Particle count ≤ 100; B: 100 < Particle count ≤ 300; C: Particle count > 300;

[0066] 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).

[0067] 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.

[0068] Table 1. Test results of different photoresist stripping solutions for OLEDs

[0069]

[0070] 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.

[0071] 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 2In 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 3 The 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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 by comprising: The formula total mass is 100%, including: 1~10% of organic alcohol amine, 2~5% of amidino compound, 0~3% of polyol, 0.01~0.2% of betaine type corrosion inhibitor, and the rest is organic solvent; 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-naphthalene carboxamidine, 2-(2-thienyl)hydroxyacetamidine, 4-methylsulfonyl benzamidine, 4-benzyl piperazine-1-carboxamidine; the betaine type corrosion inhibitor is any one or a combination of multiple of pyridine betaine, piperazine betaine, imidazoline betaine, amide betaine; The polyol is composed of small molecule polyol and macromolecular polyol in a mass ratio of 3: (1~2); the small molecule polyol is any one or a combination of multiple of glycerol, ethylene glycol, triethylene glycol, sorbitol, xylitol, erythritol; the macromolecular polyol is polypropylene glycol or polyethylene glycol, and has a single average molecular weight in the range of 400~2000 Da.

2. The photoresist stripping solution for an OLED according to claim 1, wherein The organic alcohol amine is any one or a combination of multiple of ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, 3-amino-1-propanol, N-methyl ethanolamine, N-ethyl ethanolamine, N-propyl ethanolamine, N,N-dimethyl ethanolamine, N,N-diethyl ethanolamine, diglycolamine, triglycolamine.

3. The photoresist stripping solution for an OLED according to claim 1, wherein the photoresist stripping solution is used for stripping a photoresist after a process of forming a pattern of an organic layer on a substrate. The pyridine betaine is 1-(3-thiopropyl)-2-vinyl pyridine betaine; the piperazine betaine is 1,4-dimethyl piperazine di-betaine; the imidazoline betaine is lauryl imidazoline betaine or hydroxyethyl oleic acid imidazoline betaine; the amide betaine is oleic acid amide propyl betaine.

4. The photoresist stripping solution for an OLED according to claim 1, wherein the photoresist stripping solution is used for stripping a photoresist after forming a pattern of an organic layer. The organic solvent is any one or a combination of multiple of N-methyl formamide, N-methyl pyrrolidone, N,N-dimethyl formamide, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dimethyl sulfoxide.

5. The method of claim 1 to 4, wherein the photoresist stripper for an OLED is prepared by adding 0.1 to 10 wt% of the compound of formula (I) to a solvent. The required mass of organic alcohol amine, amidino compound, polyol and betaine type corrosion inhibitor are added to the organic solvent, the system is heated to 40~50℃, and after stirring for 5~10 min, the photoresist stripping liquid for OLED is obtained.

6. The use of the photoresist stripping liquid for OLED in claim 1-4 in stripping the photoresist on the surface of the aluminum-containing OLED device.

6. The use of the photoresist stripping liquid for OLED in claim 1-4 in stripping the photoresist on the surface of the aluminum-containing OLED device.

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