Hydrogen-embrittlement-resistant precise mask plate electrolytic cleaning agent for OLED (Organic Light Emitting Diode) and preparation method thereof

Abstract

The invention discloses a hydrogen-embrittlement-resistant precise mask plate electrolytic cleaning agent for an OLED (Organic Light Emitting Diode) and a preparation method thereof, and the hydrogen-embrittlement-resistant precise mask plate electrolytic cleaning agent comprises the following components in percentage by mass: 5-10% of KOH, 0.1-0.5% of an alkali-resistant organic metal chelating agent, 0.1-1.0% of an inorganic chelating agent, 0.01-0.2% of an ampholytic surfactant and the balance of water. According to the cleaning agent, the problem of hydrogen embrittlement in the electrolytic cleaning process of the invar alloy precise mask plate is solved in a targeted manner, and the quality and reliability of the mask plate are improved. And secondly, the added reagent has good chemical stability and environmental friendliness, and does not cause adverse effects on the subsequent processing technology and environment. In addition, the method is low in cost, and considerable economic benefits are brought to the OLED manufacturing industry.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology materials, and particularly relates to a precision mask electrolytic cleaning agent for anti-hydrogen embrittlement OLEDs and a preparation method thereof. Technical Background

[0002] In the modern OLED manufacturing field, precision metal masks are crucial components, and their quality directly affects the production quality and efficiency. Among them, Invar alloy, as a commonly used material for precision metal masks, has unique properties, but faces a serious problem of hydrogen embrittlement during the electrolytic cleaning process. This patent proposes an innovative method to effectively inhibit the hydrogen embrittlement phenomenon, which is of great significance for improving the quality and performance of precision masks.

[0003] Invar alloy is a low-expansion alloy with special physical properties. Its main components are iron and nickel, and usually also contain a small amount of other elements such as cobalt and carbon. Its most remarkable feature is that it has an extremely low coefficient of thermal expansion within a certain temperature range, which makes it widely used in precision instruments, optical devices, and precision masks in the field of electronic manufacturing. This thermal stability of Invar alloy can ensure that the dimensional accuracy of the precision mask is well maintained in an environment with temperature changes, thereby ensuring the accuracy of key processes such as lithography during the manufacturing process of electronic components. In addition, Invar alloy also has good mechanical properties and processing properties, which can meet the process requirements of precision manufacturing.

[0004] During the electrolytic cleaning of precision masks, due to the occurrence of electrolytic reactions, hydrogen ions in the solution will gain electrons on the metal surface to form hydrogen atoms. Some of these hydrogen atoms will combine to form hydrogen gas and escape, but still some will diffuse into the interior of the Invar alloy. Lattice defects, stress concentration areas, etc. in the Invar alloy provide places for the aggregation of hydrogen atoms. When the hydrogen atoms accumulate to a certain concentration at these sites, they will interact with metal atoms, resulting in the occurrence of hydrogen embrittlement.

[0005] Hydrogen embrittlement is extremely harmful to precision masks. It will cause a significant reduction in the toughness and ductility of Invar alloy, making the material brittle. During subsequent processing and use, even under a small external force, the initiation and propagation of cracks may be triggered. For example, during the installation and handling of precision masks, slight vibration or stress may cause the mask to rupture, seriously affecting its service life and performance. Moreover, the cracks caused by hydrogen embrittlement may cause deviations or blockages of the light-emitting pixel points during the mask evaporation process, resulting in quality problems such as black spots and color deviation in the produced display devices, thereby significantly reducing the yield rate of OLED products. Therefore, there is an urgent need in this field for a precision mask electrolytic cleaning agent for anti-hydrogen embrittlement OLEDs to improve the performance of precision masks. Summary of the Invention

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] The first aspect of the present invention provides a precision mask electrolytic cleaning agent for anti-hydrogen embrittlement OLEDs, which is characterized in that, by mass percentage, it includes 5-10% of KOH, 0.1-0.5% of alkali-resistant organic metal chelating agents, 0.1-1.0% of inorganic chelating agents, and 0.01-0.2% of amphoteric surfactants, and the balance is water;

[0008] Further, the alkali-resistant organic metal chelating agent additive is selected from any one or more of ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), 1,2-cyclohexylenediaminetetraacetic acid (CDTA), ethylenediaminedisuccinic acid (EDDS), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepenta(methylenephosphonic acid) (DTPMP), aminotrimethylenephosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), polyamino polyether methylene phosphonic acid (PAPEMP), citric acid, tartaric acid, sodium gluconate, 2,2'-bipyridine, 1,10-phenanthroline, 8-hydroxyquinoline, and phenanthroline derivatives;

[0009] Further, the inorganic chelating agent additive is selected from any one or more of sodium polyphosphate, sodium tripolyphosphate, sodium pyrophosphate, sodium hexametaphosphate, trisodium phosphate, sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, ammonia-ammonium chloride buffer solution, ammonium sulfate, ammonium nitrate, potassium iodide, potassium bromide, potassium chloride, sodium chloride, and sodium sulfate;

[0010] Further, the amphoteric surfactant additive is selected from any one or more of sodium lauryl aminopropionate (SLAP), potassium cocoyl glycinate (PCG), sodium lauroyl sarcosinate (SLS), coconut oil diethanolamide polyoxyethylene ether, lauryl dimethyl betaine (LB), cocamidopropyl betaine (CAB), hydroxysulfobetaine (LHPB), disodium cocoamphodiacetate (), sodium lauroamphoacetate (SLI), oleyl imidazoline amphoteric surfactant (OIB), lauryl dimethylamine oxide (LDEA), sodium taurocholate (STA), glycine amphoteric surfactant (GB), and sodium N-alkyl-β-alaninate (SNBA);

[0011] The second aspect of the present invention provides a preparation method for any of the above electrolytic cleaning agents, including the following steps:

[0012] Add a certain amount of deionized water to a clean reaction kettle, and then slowly add KOH at a stirring speed of 100 - 300 rmp according to the above ratio. After complete dissolution, gradually add an alkali-resistant organic metal chelating agent, an inorganic chelating agent, and an amphoteric surfactant according to the above ratio, and finally add deionized water to make up the volume to obtain the product.

[0013] Beneficial effects

[0014] In the electrolytic cleaning agent of the present invention, the alkaline chelating agent can form stable chelates with metal ions in the solution (including impurity metal ions that may participate in the hydrogen embrittlement process), thereby reducing the catalytic effect of metal ions on the adsorption and diffusion of hydrogen atoms; the amphoteric surfactant has a unique molecular structure, and it can form a protective film on the metal surface. On the one hand, it can prevent hydrogen ions from directly contacting the metal surface and reduce the generation of hydrogen atoms; on the other hand, even if a small amount of hydrogen atoms are generated, it can also hinder the diffusion of hydrogen atoms into the metal interior, thereby effectively inhibiting the occurrence of hydrogen embrittlement.

[0015] Compared with the traditional electrolytic cleaning method, this patent has significant advantages. First, it specifically solves the hydrogen embrittlement problem in the electrolytic cleaning process of Invar alloy precision masks, improving the quality and reliability of the masks. Second, this method does not require large-scale modification of the existing electrolytic cleaning equipment and is easy to implement and promote. In addition, the added alkaline chelating agent and amphoteric surfactant have good chemical stability and environmental friendliness, and will not have an adverse impact on the subsequent processing technology and the environment. By adopting the method of this patent, the damage rate of precision masks in the electrolytic cleaning process can be effectively reduced, and display defects such as pixel point missing and uneven display caused by damaged mask performance can be reduced, improving the yield rate of product manufacturing, reducing production costs, and bringing considerable economic benefits to the OLED manufacturing industry. Specific embodiments

[0016] The present invention will be further described below in conjunction with embodiments.

[0017] The formulations of the examples and comparative examples are shown in Table 1 below:

[0018] Table 1 Formulations of examples and comparative examples

[0019]

[0020]

[0021]

[0022]

[0023] The preparation methods of the examples and comparative examples are similar. A preparation method of an electrolytic cleaning agent includes the following steps:

[0024] Add a certain amount of deionized water into a clean reaction kettle. Then, under a stirring speed of 200 rmp, slowly add KOH according to the ratios of each example and comparative example in the above table. After complete dissolution, gradually add or not add an alkali-resistant organic metal chelating agent, an inorganic chelating agent, and an amphoteric surfactant according to the above ratios. Finally, add deionized water to make up the volume to obtain the product.

[0025] The above examples and comparative examples are tested for hydrogen embrittlement resistance through the following experimental scheme:

[0026] Electrolytic cleaning experiment: Add 500 mL of the above electrolyte into an electrolytic Hull cell. Use a DC regulated power supply for power supply. The anode uses a platinum-plated titanium electrode of 2 * 2 cm, and the cathode is a precision metal mask (Mask) with a cut size of 2 * 2 cm. The distance between the two electrodes in the electrolyte is 6 cm. Connect the two poles of the power supply to the cathode and anode, with a constant current of 1 A and an electrolytic cleaning time of 24 h.

[0027] XRD test of the mask (Mask): Use XRD to test the damage and aging of the metal crystal lattice of the Mask material due to hydrogen embrittlement. The scanning speed is 5° / min, the scanning step width is 0.01°, and the scanning range is 10 - 90°. The mask (Mask) is made of invar alloy material and has diffraction peaks at 2θ angles of 50.7° and 74.5°. We take the diffraction peak at 50.7° with stronger diffraction intensity for comparison, calculate the peak area of the diffraction peak at this angle, and compare the diffraction peak areas under different electrolytes and electrolysis times to characterize the conditions with the best hydrogen embrittlement resistance. The test results are shown in Table 2.

[0028] Table 2 Experimental results of hydrogen embrittlement inhibition performance

[0029]

[0030]

[0031]

[0032]

[0033] It can be seen from the combination of the examples and comparative examples that the three additives, namely organometallic chelating agents, inorganic chelating agents, and amphoteric surfactants, all play a positive role in inhibiting hydrogen embrittlement and are all indispensable. To a certain extent, it shows that an organometallic chelating agent forms a protective film on the Mask surface during the electrolysis process. Under the appropriate conductivity provided by the inorganic chelating agent, the electrolysis process can proceed smoothly. Combining with the foam-stabilizing ability of the amphoteric surfactant, the hydrogen gas generated during the electrolysis process forms foam and escapes from the electrolyte smoothly, reducing the residence time of hydrogen gas near the metal surface. These three additives cooperate with each other and promote each other to achieve the ideal hydrogen embrittlement resistance performance.

[0034] From the comparison between Example 1 and Comparative Examples 1-4, it can be concluded that the organometallic chelating agent plays a key role here. A suitable alkali-resistant organic chelating agent can provide a more stable and dense protective film.

[0035] From the comparison results of Example 1, Example 2, and Example 5, it shows that sodium gluconate (SDG) has a better hydrogen embrittlement resistance effect than diethylenetriamine pentamethylenephosphonic acid (DTPMP) and ethylenediaminetetraacetic acid (EDTA).

[0036] From the results of Examples 5-7, it can be inferred that trisodium phosphate and oleic acid-based imidazoline amphoteric surfactant (OIB) combined with sodium gluconate (SDG) can exhibit more excellent hydrogen embrittlement resistance performance.

[0037] From the results of Comparative Examples 5-17, it can be inferred that by changing different organometallic chelating agents, inorganic chelating agents, and amphoteric surfactants respectively, a hydrogen embrittlement effect occurs.

[0038] From the results of Comparative Examples 18-72, it can be inferred that by changing the ratios of different organometallic chelating agents, inorganic chelating agents, and amphoteric surfactants respectively, a hydrogen embrittlement effect occurs.

[0039] In summary, by adding a suitable alkali-resistant organometallic chelating agent, inorganic chelating agent, and amphoteric surfactant, the present invention can significantly improve the hydrogen embrittlement resistance performance of the electrolyte and effectively extend the service life of the precision mask.

Claims

1. A precision mask electrolytic cleaning agent for hydrogen embrittlement OLED, characterized in that: Calculated by mass percentage, it includes 5-10% KOH, 0.1-0.5% alkali-resistant organic metal chelating agent, 0.1-1.0% inorganic chelating agent and 0.01-0.2% amphoteric surfactant, and the balance is water.

2. The electrolytic cleaning agent for the precision mask plate for OLEDs resistant to hydrogen embrittlement according to claim 1, characterized in that: The alkali-resistant organic metal chelating agent additive is selected from any one or more of ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), 1,2-cyclohexanediaminetetraacetic acid (CDTA), ethylenediaminedisuccinic acid (EDDS), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentamethylenephosphonic acid (DTPMP), aminotrimethylenephosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), polyaminopolyethermethylenephosphonic acid (PAPEMP), citric acid, tartaric acid, sodium gluconate, 2,2'-bipyridine, 1,10-phenanthroline, 8-hydroxyquinoline, and o-phenanthroline derivatives.

3. The electrolytic cleaning agent for the precision mask plate for OLEDs against hydrogen embrittlement according to claim 1, characterized in that: The inorganic chelating agent additive is selected from any one or more of sodium polyphosphate, sodium tripolyphosphate, sodium pyrophosphate, sodium hexametaphosphate, trisodium phosphate, sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, ammonia-ammonium chloride buffer, ammonium sulfate, ammonium nitrate, potassium iodide, potassium bromide, potassium chloride, sodium chloride, and sodium sulfate.

4. The electrolytic cleaning agent for the precision mask plate for OLEDs against hydrogen embrittlement according to claim 1, characterized in that: The amphoteric surfactant additive is selected from any one or more of sodium dodecylaminopropionate (SLAP), potassium cocoyl glycinate (PCG), sodium lauroyl sarcosinate (SLS), cocoyl diethanolamide polyoxyethylene ether, dodecyl dimethyl betaine (LB), cocamidopropyl betaine (CAB), hydroxysulfobetaine (LHPB), disodium cocoamphodiacetate, sodium lauroamphoacetate (SLI), oleic imidazoline amphoteric surfactant (OIB), dodecyl dimethyl amine oxide (LDEA), sodium taurocholate (STA), glycine amphoteric surfactant (GB), and sodium N-alkyl-β-alanine (SNBA).

5. A method for preparing the electrolytic cleaning agent according to any one of claims 1 to 4, characterized in that: The following steps are involved: Add a certain amount of deionized water to a clean reactor, then slowly add KOH according to the above ratio at a stirring speed of 100-300 rpm, and after it is completely dissolved, gradually add an alkali-resistant organic metal chelating agent, an inorganic chelating agent and an amphoteric surfactant according to the above ratio, and finally add deionized water to make up to volume.

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