Aqueous photoresist stripping liquid for AMOLED field and preparation method thereof

Abstract

The invention relates to the technical field of stripping liquids, and discloses a water-based photoresist stripping liquid for the AMOLED (Active Matrix / Organic Light Emitting Diode) field, which comprises the following components in percentage by mass: 15-20% of 2, 2-dimethylolpropionic acid, 25-30% of diethylene glycol monobutyl ether, 8-10% of diethylene glycol monomethyl ether, 5-8% of diethanol amine, 1.5-3% of a metal protective agent, 0.5-1% of a surfactant and the balance of pure water. According to the stripping liquid, raw materials including 2, 2-dimethylolpropionic acid, diethylene glycol monomethyl ether and diethylene glycol monobutyl ether are subjected to double-tower distillation, metal ions are reduced to 100 ppt, the pollution possibility is eliminated, and metal impurities and granularity in the stripping liquid production process are controlled. According to the invention, the proper metal protective agent and surfactant are adopted, so that the metal silver is protected in the stripping process, the surface tension is reduced, the permeability of the solution is improved, and the problem of photoresist residue is solved.

Description

Technical Field

[0001] The invention relates to the technical field of stripping solutions, and in particular to an aqueous photoresist stripping solution in the AMOLED field and a preparation method thereof. Background Art

[0002] Amid the rapid progress in the global display technology field, active matrix organic light-emitting diode (AMOLED) displays, as a leading display technology, are gradually becoming the mainstream of the market. AMOLED displays are widely used in smartphones, TVs, laptops, and other wearable devices and portable electronic products due to their excellent color performance, high contrast, fast response time, and low power consumption.

[0003] With the development of science and technology, the demand for stripping liquid in the AMOLED field is increasing, and the technical level requirements are getting higher and higher. Traditional stripping liquid will corrode the metal silver or dielectric layer on the microcircuit, resulting in reduced performance of the final semiconductor device and unable to meet the requirements of high resolution.

[0004] Therefore, developing an aqueous photoresist stripping solution for the AMOLED field, which has a fast stripping speed, does not corrode metallic silver, and has no photoresist residue after stripping, is a problem that needs to be solved urgently by the present invention. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an aqueous photoresist stripping solution for the AMOLED field and a preparation method thereof. The stripping solution of the present invention has stable components, fast film stripping speed, no corrosion to metallic silver, simple operation, adaptability to a variety of equipment, large process tolerance, no fluoride, biodegradability, good water solubility, the product can be directly washed with water, and has high comprehensive benefits.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An aqueous photoresist stripping solution for AMOLED field, comprising the following components by mass percentage:

[0008]

[0009]

[0010] Preferably, the metal ions of the 2,2-dihydroxymethylpropionic acid, diethylene glycol methyl ether and diethylene glycol butyl ether are all no higher than 100 ppt.

[0011] More preferably, the 2,2-dihydroxymethylpropionic acid, diethylene glycol methyl ether and diethylene glycol butyl ether are all industrial-grade raw materials and the metal ions are reduced to 100 ppt through double-tower distillation.

[0012] Preferably, the metal protective agent is one or a combination of methimazole, water-soluble imidazoline, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol, sodium carboxymethyl cellulose, cetylpyridinium bromide, potassium sorbate, and nitroxide free radical piperidinol.

[0013] Preferably, the metal protective agent is prepared by the following steps: in a clean room, pure water and diethanolamine are added at room temperature and stirred for 20 minutes, then steam is turned on to raise the temperature to 65°C, water-soluble imidazoline and cetylpyridinium bromide are added and stirred for 3 hours, steam is turned off, cooling water is turned on to reduce the temperature of the reactor to 30°C, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is added and stirred for 30 minutes;

[0014] The mass ratio of pure water, diethanolamine, water-soluble imidazoline, cetylpyridinium bromide and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is 5:3:0.5:(0.2-0.4):(0.19-0.33).

[0015] More preferably, the mass ratio of the pure water, diethanolamine, water-soluble imidazoline, cetylpyridinium bromide, and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is 5:3:0.5:0.2:0.19.

[0016] Preferably, the surfactant is one or a combination of glycerol, polyethylene glycol, fatty alcohol polyoxyethylene ether, stearic acid monoglyceride, lauric acid, dioctyl sodium sulfosuccinate, and ethylene bisstearamide.

[0017] Preferably, the surfactant is prepared by the following steps: in a purified space, at room temperature, glycerol, polyethylene glycol, lauric acid, and fatty alcohol polyoxyethylene ether are mixed and stirred for 1 hour; wherein the mass ratio of glycerol, polyethylene glycol, lauric acid, and fatty alcohol polyoxyethylene ether is 8:(2.0-4.5):(0.6-0.8):(0.12-0.22).

[0018] More preferably, the mass ratio of the glycerol, polyethylene glycol, lauric acid and fatty alcohol polyoxyethylene ether is 8:2:0.6:0.12.

[0019] Another object of the present invention is to disclose a method for preparing the above-mentioned aqueous photoresist stripping solution for AMOLED, comprising the following steps:

[0020] (1) Add pure water, 2,2-dimethylolpropionic acid and diethanolamine into the purification space and stir for 30 minutes.

[0021] (2) then adding diethylene glycol butyl ether and diethylene glycol methyl ether and stirring for 30 minutes;

[0022] (3) Finally, add metal protective agent and surfactant, stir for 2 hours, take samples to detect content and metal ions, and if qualified, filter through 3-stage filter for 2 hours, take samples to detect particles, and if qualified, package to obtain the target product.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The stripping liquid of the present invention reduces the metal ions of the raw materials 2,2-dimethylol propionic acid, diethylene glycol methyl ether and diethylene glycol butyl ether to 100ppt through double-tower distillation. A three-level filtration mode is used to remove particles during the finished product configuration process. In a 100-level purification space, a fully automatic packaging system is used to eliminate the possibility of contamination, so that the metal impurities and particle size in the stripping liquid production process are controlled.

[0025] The stripping solution of the present invention adopts a suitable metal protective agent, and during the stripping process, an oxide film is generated on the metal surface to prevent the metal from corroding the metal layer, thereby protecting the metallic silver during the stripping process.

[0026] The stripping solution of the present invention adopts a suitable surfactant to reduce surface tension, increase the permeability of the solution, and solve the problem of photoresist residue. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a plan view observed under a scanning electron microscope after stripping with the stripping solution of Example 1;

[0028] Figure 2 is a cross-sectional view observed under a scanning electron microscope after stripping with the stripping solution of Example 2;

[0029] Figure 3 This is a cross-sectional view observed under a scanning electron microscope after the stripping solution of Comparative Example 1 was stripped;

[0030] Figure 4 This is a plan view observed under a scanning electron microscope after the stripping solution of Comparative Example 2 was stripped;

[0031] Figure 5 This is a cross-sectional view observed under a scanning electron microscope after stripping with the stripping solution of Comparative Example 3. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with examples, but it should be noted that the examples do not limit the scope of protection claimed for the present invention.

[0033] An aqueous photoresist stripping solution for AMOLED field, comprising the following components by mass percentage:

[0034]

[0035] Among them, the metal ions of 2,2-dihydroxymethylpropionic acid, diethylene glycol methyl ether and diethylene glycol butyl ether are all less than 100ppt.

[0036] In the embodiment of the present invention, 2,2-dimethylol propionic acid, diethylene glycol methyl ether, and diethylene glycol butyl ether are all industrial-grade raw materials, and the metal ions are reduced to 100ppt by double-tower distillation. During the finished product configuration process, a three-level filtration mode is used to remove particles, and a fully automatic packaging system is used in a 100-level purification space to eliminate the possibility of contamination.

[0037] The metal protective agent is one or a combination of methimazole, water-soluble imidazoline, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol, sodium carboxymethyl cellulose, cetylpyridinium bromide, potassium sorbate, and nitroxide free radical piperidinol.

[0038] The metal protective agent is prepared by the following steps: in a clean room, pure water and diethanolamine are added at room temperature and stirred for 20 minutes, then steam is turned on to raise the temperature to 65°C, water-soluble imidazoline and cetylpyridinium bromide are added and stirred for 3 hours, steam is turned off, cooling water is turned on to reduce the temperature of the reactor to 30°C, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is added and stirred for 30 minutes;

[0039] The mass ratio of pure water, diethanolamine, water-soluble imidazoline, cetylpyridinium bromide and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is 5:3:0.5:(0.2-0.4):(0.19-0.33).

[0040] The metal protective agent needs to be dissolved in pure water and diethanolamine during the preparation process. The pure water and diethanolamine used in the preparation method of the metal protective agent are not the pure water and diethanolamine in the above-mentioned photoresist stripping solution formula.

[0041] In an embodiment of the present invention, the mass ratio of pure water, diethanolamine, water-soluble imidazoline, cetylpyridinium bromide, and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is 5:3:0.5:0.2:0.19.

[0042] The surfactant is one or a combination of glycerol, polyethylene glycol, fatty alcohol polyoxyethylene ether, stearic acid monoglyceride, lauric acid, dioctyl sodium sulfosuccinate, and ethylene bisstearamide.

[0043] The surfactant is prepared by the following steps: in a purified space, at room temperature, glycerol, polyethylene glycol, lauric acid, and fatty alcohol polyoxyethylene ether are mixed and stirred for 1 hour; wherein the mass ratio of glycerol, polyethylene glycol, lauric acid, and fatty alcohol polyoxyethylene ether is 8:(2.0-4.5):(0.6-0.8):(0.12-0.22).

[0044] In an embodiment of the present invention, the mass ratio of glycerol, polyethylene glycol, lauric acid and fatty alcohol polyoxyethylene ether is 8:2:0.6:0.12.

[0045] The above-mentioned method for preparing an aqueous photoresist stripping solution for the AMOLED field comprises the following steps:

[0046] Add pure water, 2,2-dihydroxymethylpropionic acid and diethanolamine into the purification space and stir for 30 minutes; then add diethylene glycol butyl ether and diethylene glycol methyl ether and stir for 30 minutes; finally add metal protective agent and surfactant, stir for 2 hours, take samples to detect the content and metal ions, and after passing the test, filter through a three-stage filter for 2 hours, take samples to test the particles, and package them to obtain the target product after passing the test.

[0047] In order to illustrate the performance advantages of the semiconductor-grade single crystal silicon thinning solution of the present invention, the following is described by comparing Examples 1-9 with Comparative Examples 1-4:

[0048] Example 1

[0049] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 15% of 2,2-dihydroxymethylpropionic acid, 25% of diethylene glycol butyl ether, 8% of diethylene glycol methyl ether, 5% of diethanolamine, 1.5% of metal protective agent, 0.5% of surfactant, and 45% of pure water.

[0050] Example 2

[0051] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 18% of 2,2-dihydroxymethylpropionic acid, 26% of diethylene glycol butyl ether, 9% of diethylene glycol methyl ether, 6% of diethanolamine, 1.5% of metal protective agent, 0.5% of surfactant, and 39% of pure water.

[0052] Example 3

[0053] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 19% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 9% of diethylene glycol methyl ether, 7% of diethanolamine, 2% of metal protective agent, 0.8% of surfactant, and 35.2% of pure water.

[0054] Example 4

[0055] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 20% of 2,2-dimethylol propionic acid, 28% of diethylene glycol butyl ether, 9% of diethylene glycol methyl ether, 8% of diethanolamine, 2.5% of metal protective agent, 0.9% of surfactant, and 31.6% of pure water.

[0056] Example 5

[0057] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 18% of 2,2-dihydroxymethylpropionic acid, 30% of diethylene glycol butyl ether, 10% of diethylene glycol methyl ether, 6% of diethanolamine, 2.5% of metal protective agent, 0.5% of surfactant, and 33% of pure water.

[0058] Example 6

[0059] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 17% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 7.5% of diethylene glycol methyl ether, 8% of diethanolamine, 3% of metal protective agent, 0.6% of surfactant, and 36.9% of pure water.

[0060] Example 7

[0061] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 17% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 7.5% of diethylene glycol methyl ether, 8% of diethanolamine, 2.5% of metal protective agent, 0.6% of surfactant, and 37.4% of pure water.

[0062] Example 8

[0063] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 17% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 7.5% of diethylene glycol methyl ether, 8% of diethanolamine, 2% of metal protective agent, 0.6% of surfactant, and 37.9% of pure water.

[0064] Example 9

[0065] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 17% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 7.5% of diethylene glycol methyl ether, 8% of diethanolamine, 1.5% of metal protective agent, 0.6% of surfactant, and 38.4% of pure water.

[0066] Comparative Example 1 (without metal protective agent)

[0067] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 19% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 9% of diethylene glycol methyl ether, 7% of diethanolamine, 0.8% of surfactant, and 37.2% of pure water.

[0068] Comparative Example 2 (without surfactant)

[0069] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 19% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 9% of diethylene glycol methyl ether, 7% of diethanolamine, 2% of metal protective agent, and 36.0% of pure water.

[0070] Comparative Example 3

[0071] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 19% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 9% of diethylene glycol methyl ether, 7% of diethanolamine, 1.0% of metal protective agent, 0.3% of surfactant, and 36.7% of pure water.

[0072] Comparative column 4 (without diethylene glycol methyl ether)

[0073] The aqueous photoresist stripping solution is prepared according to the following components in mass percentage: 19% of 2,2-dihydroxymethylpropionic acid, 27% of diethylene glycol butyl ether, 7% of diethanolamine, 2% of metal protective agent, 0.8% of surfactant, and 44.2% of pure water.

[0074] Photoresist stripping solutions were prepared according to Examples 1-9 and Comparative Examples 1-4, and the performance of the stripping solutions was tested respectively:

[0075] (1) Take 1L of photoresist stripping solution in a beaker and heat it to 50°C in a water bath. Immerse the etched sample in the stripping solution for 20 minutes, take it out, rinse it immediately with pure water, and then blow it dry with high-purity nitrogen.

[0076] (2) Slicing the stripped substrate and observing whether there is photoresist residue and metal silver corrosion under a scanning electron microscope;

[0077] (3) The silver ion content in the stripping solution impregnated with the semiconductor is detected using an inductively coupled plasma mass spectrometer (ICP_MS). The lower the metal ion content, the better the anti-corrosion performance of the stripping solution on the metallic silver on the semiconductor.

[0078] The test results are shown in the figure below:

[0079]

[0080]

[0081] It can be seen from the test results of Examples 1-9 that the stripping solution prepared in the present application not only has a good stripping effect on the photoresist, but also has a good anti-corrosion effect on metallic silver.

[0082] In Example 1 and Example 2, the amount of metal protective agent added was 1.5%, and there was no obvious damage under the electron microscope. Figure 1-2 As shown, the silver ion concentration in the solution is about 0.25 ppb.

[0083] When the amount of metal protective agent added is reduced, the corrosion of metal silver increases. For example, in Examples 6-9, the concentration of silver ions tends to increase, indicating that under the same conditions, the greater the amount of metal protective agent added, the better the anti-corrosion effect.

[0084] When there is no metal protective agent in the stripping solution, such as in Comparative Example 1, the silver ion concentration rises to 1.88 ppb, and the metal silver is obviously corroded under the scanning electron microscope, such as Figure 3 shown.

[0085] In Comparative Example 2, there is no surfactant, the permeability of the solution decreases, the stripping efficiency of the photoresist decreases, and the photoresist residue on the surface is very serious. Figure 4 shown.

[0086] In comparative example 3, the amount of metal protective agent added was reduced to 1%, and the silver ion concentration of the solution after stripping was relatively high, reaching 0.77 ppb. At the same time, the metal silver was slightly damaged under the scanning electron microscope (such as Figure 5 As shown), in comparison column 3, the amount of surfactant added is less than 0.3%, and the photoresist residue is relatively better than that of comparative example 2, but there is still a gap compared with embodiment 1.

[0087] In comparison column 4, due to the lack of diethylene glycol methyl ether, the stripping efficiency is greatly reduced and cannot meet the process requirements.

[0088] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An aqueous photoresist stripping solution for AMOLED field, characterized in that: The composition includes the following components by mass percentage:

2. The aqueous photoresist stripping solution for AMOLED according to claim 1, characterized in that: The metal ions of the 2,2-dihydroxymethylpropionic acid, diethylene glycol methyl ether and diethylene glycol butyl ether are all less than 100 ppt.

3. The aqueous photoresist stripping solution for AMOLED according to claim 2, characterized in that: The 2,2-dihydroxymethylpropionic acid, diethylene glycol methyl ether and diethylene glycol butyl ether are all industrial-grade raw materials, and the metal ions are reduced to 100 ppt through double-tower distillation.

4. The aqueous photoresist stripping solution for AMOLED according to claim 1, characterized in that: The metal protective agent is one or a combination of methimazole, water-soluble imidazoline, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol, sodium carboxymethyl cellulose, cetylpyridinium bromide, potassium sorbate, and nitroxide free radical piperidinol.

5. The aqueous photoresist stripping solution for AMOLED according to claim 4, characterized in that: The metal protective agent is prepared by the following steps: in a purified space, pure water and diethanolamine are added at room temperature and stirred for 20 minutes, then steam is turned on to raise the temperature to 65° C., water-soluble imidazoline and cetylpyridinium bromide are added and stirred for 3 hours, steam is turned off, cooling water is turned on to reduce the temperature of the reactor to 30° C., 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is added and stirred for 30 minutes; The mass ratio of pure water, diethanolamine, water-soluble imidazoline, cetylpyridinium bromide and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is 5:3:0.5:(0.2-0.4):(0.19-0.33).

6. The aqueous photoresist stripping solution for AMOLED according to claim 5, characterized in that: The mass ratio of the pure water, diethanolamine, water-soluble imidazoline, cetylpyridinium bromide and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]amino]diethanol is 5:3:0.5:0.2:0.

19.

7. The aqueous photoresist stripping solution for AMOLED according to claim 1, characterized in that: The surfactant is one or a combination of glycerol, polyethylene glycol, fatty alcohol polyoxyethylene ether, stearic acid monoglyceride, lauric acid, dioctyl sodium sulfosuccinate, and ethylene bisstearamide.

8. The aqueous photoresist stripping solution for AMOLED according to claim 7, characterized in that: The surfactant is prepared by the following steps: in a purified space, at room temperature, glycerol, polyethylene glycol, lauric acid, and fatty alcohol polyoxyethylene ether are mixed and stirred for 1 hour; wherein the mass ratio of glycerol, polyethylene glycol, lauric acid, and fatty alcohol polyoxyethylene ether is 8:(2.0-4.5):(0.6-0.8):(0.12-0.22).

9. The aqueous photoresist stripping solution for AMOLED according to claim 8, characterized in that: The mass ratio of the glycerol, polyethylene glycol, lauric acid and fatty alcohol polyoxyethylene ether is 8:2:0.6:0.

12.

10. The method for preparing an aqueous photoresist stripping solution for AMOLED according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Add pure water, 2,2-dimethylolpropionic acid and diethanolamine into the purification space and stir for 30 minutes. (2) then adding diethylene glycol butyl ether and diethylene glycol methyl ether and stirring for 30 minutes; (3) Finally, add metal protective agent and surfactant, stir for 2 hours, take samples to detect content and metal ions, and if qualified, filter through 3-stage filter for 2 hours, take samples to detect particles, and if qualified, package to obtain the target product.

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