Cleaning process for removing smudginess on edge of chip blocking plug

Abstract

The invention relates to the field of semiconductor cleaning, and discloses a cleaning process for removing dirt on the edge of a chip card plug, which comprises the following steps of: sequentially carrying out ultrapure water ultrasonic cleaning, compound organic solution cleaning, HQDR cleaning, mechanical scrubbing, SC2 cleaning, QDR cleaning and spin-drying on the card plug. According to a cleaning mechanism, the cleaning process is integrated and optimized, cleaning parameters are accurately controlled, pollutants on the surfaces and gaps of the plugs are treated in a targeted step-by-step and circulating mode, and the method has the advantages of being better in particulate matter cleaning effect, more thorough in stubborn pollutant removal and the like; the smudginess problems of wafer edge particle aggregation, metal ion exceeding and the like caused by smudginess of the card plug are effectively solved, so that rework caused by edge pollution is effectively reduced, secondary pollution of the wafer is fundamentally avoided, the quality of the wafer is greatly improved, the product percent of pass is improved, and the service life of the card plug is prolonged; operation is easy and convenient, cleaning cost is effectively reduced, and good popularization prospects are achieved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor cleaning, and more specifically to a cleaning process for removing dirt from the edges of wafer jams. Background Technology

[0002] Semiconductor manufacturing is a complex process involving multiple high-precision steps, each requiring extremely high cleanliness of the wafer surface to ensure the performance and reliability of the final device. Similarly, wafer chucks (the fixtures used to hold the wafers in place) also need to maintain an equivalent level of cleanliness to ensure that the wafers are not subject to secondary contamination during manufacturing and handling.

[0003] Wafer edges, especially chuck edges, are a critical but often overlooked area in the manufacturing process. Due to their unique geometry and contact with the chuck during handling, these edge regions are prone to accumulating contaminants. If these contaminants are not removed promptly, they can adversely affect subsequent process steps.

[0004] Cleaning the edges of wafer plugs presents the following challenges: ① Uneven cleaning: The complex geometry of the edge region makes it difficult to ensure uniform coverage of the cleaning solution or medium using conventional cleaning methods; ② Diverse types of contaminants: Contaminants in the edge region may include particles, organic matter, metal ions, etc.; ③ Mechanical damage: The edges of the plug are prone to damage such as burrs, white spots, and vertical lines during brushing and other processes. Therefore, how to thoroughly clean the dirt on the edges of wafer plugs is an important technical problem. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a cleaning process for removing dirt from the edges of wafer jammers, the technical solution of which is as follows: A cleaning process for removing dirt from the edges of a wafer jammer includes the following steps: (1) Ultrapure water ultrasonic cleaning: Immerse the cartridge completely in ultrapure water for 5-15 minutes at a temperature of 70-80℃ and an ultrasonic frequency of 25-55KHz. (2) Cleaning with compound organic solution: The stopper is completely immersed in compound organic solution and cleaned by bottom ultrasonication; (3) HQDR cleaning: Cleaning is performed with heated ultrapure water, including spraying, bubbling, rapid drainage and overflow; the cleaning temperature is 60-75℃ and the cleaning time is 4-20min; (4) Mechanical cleaning: Use dust-free clean cotton swabs / brushes to wipe the gaps of the blockage and spray with water; (5) SC2 cleaning: The cleaning reagents include HCl, H2O2 and H2O; the cleaning temperature is 60-80℃ and the cleaning time is 5-10min; (6) QDR cleaning: Clean with ultrapure water at room temperature, including spraying, bubbling, rapid drainage and overflow; cleaning time is 4-6 minutes; (7) Spin-drying: Dry the stopper in a centrifugal rotation state at a temperature of 30-50℃, a drying time of 5-8 min, and a centrifugal speed of 500-2300 r / min.

[0006] Furthermore, in step (1), the ultrasonic washing time with ultrapure water is 10-15 min; the soaking temperature is 70-75℃; and the ultrasonic frequency is 30-45KHz.

[0007] Furthermore, the ultrasonic washing time with ultrapure water is 15 minutes; the immersion temperature is 70°C; and the ultrasonic frequency is 40 kHz.

[0008] Furthermore, the organic solution in step (2) is composed of water and industrial-grade fatty acid methyl ester ethoxylate sulfonate, N-methylpyrrolidone, N-methyldiethanolamine, sodium silicate, polyvinylpyrrolidone, and fatty alcohol polyoxyethylene ether. The mass percentages of fatty acid methyl ester ethoxylate sulfonate, N-methylpyrrolidone, N-methyldiethanolamine, sodium silicate, polyvinylpyrrolidone, and fatty alcohol polyoxyethylene ether are 2%-5%, 10%-15%, 3%-5%, 1%-3%, 0.5%-1%, and 2%-5%, respectively, and are made up to 100% by water. The cleaning time is 10-20 min, the cleaning temperature is 25-55℃, and the ultrasonic frequency is 25-55KHz.

[0009] Furthermore, the mass percentages of the fatty acid methyl ester ethoxylate sulfonate, N-methylpyrrolidone, N-methyldiethanolamine, sodium silicate, polyvinylpyrrolidone, fatty alcohol polyoxyethylene ether, and water are 3%, 12%, 4%, 2%, 0.75%, 4%, and 74.25%, respectively; the cleaning time is 15 minutes, the cleaning temperature is 38°C, and the ultrasonic frequency is 40 kHz.

[0010] Furthermore, the cleaning temperature in step (3) is 65-75℃, and the cleaning time is 5-10 min.

[0011] Furthermore, the cleaning temperature in step (3) is 70°C and the cleaning time is 8 minutes.

[0012] Furthermore, in step (4), the cotton swabs / brushes are made of one or more of the following: a polyester dust-free cloth head, a sponge head, and polyvinyl alcohol.

[0013] Furthermore, in step (5), the mass concentration of HCl reagent is 36%-38%, the mass concentration of H2O2 reagent is 30%-32%, the volume ratio of HCl, H2O2 and H2O is 1:(0.5-2.5):(7.5-12.5), the cleaning temperature is 65-75℃, and the cleaning time is 5-8min.

[0014] Furthermore, in step (5), the volume ratio of HCl, H2O2 and H2O is 1:1:(9-10.5); the cleaning temperature is 65℃ and the cleaning time is 5min.

[0015] Compared with the prior art, the cleaning process for removing dirt from the edge of wafer jamming provided by the present invention has the following beneficial technical effects: 1. This invention integrates and optimizes the cleaning process based on the cleaning mechanism, resulting in a more targeted cleaning process, a more complete cleaning procedure, and precise control of cleaning parameters. The reagent formula is also more rationally designed, featuring better particulate matter cleaning effect and more thorough removal of stubborn contaminants. It effectively solves the contamination problems caused by jammed wafers, such as particle aggregation at the wafer edge and excessive metal ions, thereby effectively reducing rework caused by edge contamination, fundamentally avoiding secondary contamination of wafers, significantly improving wafer quality, increasing product qualification rate, and extending the service life of jammed wafers.

[0016] 2. This invention features targeted, step-by-step, cyclical treatment of contaminants on the surface and in the crevices of the cartridge, reducing the residual amount of particles and metal ions. The invention prioritizes ultrasonic washing pretreatment with ultrapure water, which softens organic or partially inorganic contaminants on the cartridge surface and in the crevices, facilitating subsequent cleaning with a compounded organic solution. Cleaning with an organic solution dissolves and removes organic contaminants such as wax from the cartridge surface, while HQDR and ultrasound remove inorganic substances and particles adhering to the cartridge. SC2 cleaning complexes and dissolves metal ion contaminants on the wafer surface, effectively removing metal ions and preventing their redeposition onto the cartridge surface. Hydrochloric acid and hydrogen peroxide chemically remove particles adhering to the cartridge surface, especially those chemically bonded to the surface. Ultimately, this achieves the goal of minimizing contaminant residue on the cartridge surface and in the crevices, improving cartridge surface cleanliness and cartridge utilization.

[0017] 3. The cleaning method of the present invention is simple and easy to operate, effectively reduces cleaning costs, and has a good prospect for promotion. Attached Figure Description

[0018] Figure 1 , Figure 2 These are comparison images of test results (using Candela 8520 equipment) for wafers with ≥0.2μm particles provided before the implementation of this invention. Figure 3 , Figure 4These are comparative images showing the test results (equipment: Candela 8520) of wafers with ≥0.2μm particles after the cleaning process of Example 1 according to the present invention; Figure 5 , Figure 6 These are comparative images showing the test results (equipment: Candela 8520) of wafers with ≥0.2μm particles after the cleaning process of Example 2 of this invention; Figure 7 , Figure 8 , Figure 9 , Figure 10 Comparison images of test results (equipment: Candela 8520) for wafers with ≥0.2μm particles provided for the comparison group of conventional cleaning techniques. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings; unless otherwise specified in the description, all are conventional technologies and will not be repeated.

[0020] The overall implementation scheme of this invention is first described as follows: A cleaning process for removing dirt from the edges of a wafer jammer includes the following steps: (1) Ultrapure water ultrasonic cleaning: The stopper (preferably a turnover PP / PET stopper and / or a cleaning PFA / PTFE stopper) is completely immersed in ultrapure water for 5-15 minutes at an immersion temperature of 70-80℃ and an ultrasonic frequency of 25-55KHz; a more preferred method is an ultrapure water ultrasonic cleaning time of 10-15 minutes at an immersion temperature of 70-75℃ and an ultrasonic frequency of 30-45KHz; the most preferred method is an ultrapure water ultrasonic cleaning time of 15 minutes at an immersion temperature of 70℃ and an ultrasonic frequency of 40KHz. The resistivity of ultrapure water... More preferred The optimal choice is The particle size in the ultrapure water is preferably ≤350 particles / L for the 0.1-0.2μm range, ≤100 particles / L for the 0.2-0.5μm range, ≤50 particles / L for the 0.5-1.0μm range, and ≤20 particles / L for the >1.0μm range. The concentration of metal ions (Al, Sb, As, Ba, B, Cr, Ca, Cu, Fe, Pb, Li, Mg, Mn, Ni, K, Na, Sr, Sn, Ti, V, Zn) is preferably ≤0.01ppb. This invention employs ultrasonic washing with ultrapure water, accelerating the dissolution and dispersion of contaminants by increasing temperature. Thermal diffusion increases the molecular motion rate, making it easier for contaminants to detach from the surface. Many contaminants (such as wax) decrease in viscosity at high temperatures, making them easier to rinse away. The cavitation effect of ultrasound can generate local high pressure, which can effectively decompose and peel off dirt adhering to the surface of the plug. The micro-jets of ultrasound can penetrate into tiny gaps and remove dirt that is difficult to reach by traditional cleaning methods.

[0021] (2) Cleaning with a compound organic solution: The stopper is completely immersed in the compound organic solution and cleaned by bottom ultrasonication; the compound organic solution is composed of water and industrial-grade fatty acid methyl ester ethoxylate sulfonate (FMES), N-methylpyrrolidone (NMP), N-methyldiethanolamine (MDEA), sodium silicate (Na2SiO3), polyvinylpyrrolidone (PVP), and fatty alcohol polyoxyethylene ether. Among them, fatty acid methyl ester ethoxylate sulfonate (FMES), N-methylpyrrolidone (NMP), N-methyldiethanolamine (MDEA), sodium silicate (Na2SiO3), and polyvinyl alcohol are added. The mass percentages of pyrrolidone (PVP), fatty alcohol polyoxyethylene ether are 2%-5%, 10%-15%, 3%-5%, 1%-3%, 0.5%-1%, and 2%-5%, respectively, and are made up to 100% by water. The optimal composition is as follows: the mass percentages of fatty acid methyl ester ethoxylate sulfonate (FMES), N-methylpyrrolidone (NMP), N-methyldiethanolamine (MDEA), sodium silicate (Na2SiO3), polyvinylpyrrolidone (PVP), fatty alcohol polyoxyethylene ether, and water are 3%, 12%, 4%, 2%, 0.75%, 4%, and 74.25%, respectively. The cleaning time is 10-20 min, the cleaning temperature is 25-55℃, and the ultrasonic frequency is 25-55 kHz; a better option is a cleaning time of 10-15 min, a cleaning temperature of 35-45℃, and an ultrasonic frequency of 30-45 kHz; the most preferred option is a cleaning time of 15 min, a cleaning temperature of 38℃, and an ultrasonic frequency of 40 kHz. FMES in organic solutions exhibits excellent detergency and emulsification properties, helping to decompose and remove waxes and greases. Furthermore, FMES introduces cyclic sulfonated end-cap structures at both ends of its molecular chain, giving it a three-dimensional molecular chain structure, resulting in better dispersibility and excellent anti-back-fogging properties. NMP is a highly selective and stable polar solvent that effectively dissolves various organic substances, including waxes, greases, and other contaminants. MDEA is an organic amine that enhances the detergency of cleaning agents and can strengthen performance when used in combination with FMES and NMP. Nano-sized Na₂SiO₃ can achieve a higher contact area in solution, improving its chelation effect and exhibiting excellent detergency, helping to break down stubborn stains and grease on stuck surfaces. Fatty alcohol polyoxyethylene ethers can oriented on the surface of the solution and significantly reduce surface tension, synergistically promoting the effective penetration of active ingredients in the solution into the dirt on the stuck surface.

[0022] (3) HQDR cleaning: Cleaning is performed using heated ultrapure water, including spraying, bubbling, rapid discharge, and overflow; the cleaning temperature is 60-75℃, and the cleaning time is 4-20 min; a preferred option is a cleaning temperature of 65-75℃ and a cleaning time of 5-10 min; the optimal option is a cleaning temperature of 70℃ and a cleaning time of 8 min. Heating is used to accelerate the dissolution and dispersion of contaminants; spraying uses high-pressure jets of ultrapure water to clean the surface of the plug, removing particulate matter, loose contaminants, and cleaning residue; bubbling introduces air bubbles into the ultrapure water to enhance the cleaning effect. The formation, collapse, and movement of the bubbles physically disturb the liquid, promoting the removal of surface contaminants; rapid discharge is the quick discharge of cleaning water to reduce the chance of contaminant re-adhesion. Overflow continuously refreshes the ultrapure water to maintain its purity.

[0023] (4) Mechanical scrubbing: Use clean cotton swabs / brushes to wipe the crevices while spraying water; the cotton swabs / brushes should be made of one or more of the following: clean polyester cloth, sponge, and polyvinyl alcohol. Continuous water spraying during the scrubbing process helps to accelerate the removal of organic and inorganic particles.

[0024] (5) SC2 cleaning: The cleaning reagents include HCl, H2O2, and H2O. The mass concentration of HCl is 36%-38%, and the mass concentration of H2O2 is 30%-32%. The volume ratio of HCl, H2O2, and H2O is 1:(0.5-2.5):(7.5-12.5), the cleaning temperature is 60-80℃, and the cleaning time is 5-10 min; a more preferred scheme is: the volume ratio of HCl, H2O2, and H2O is 1:(0.8-1.2):(8-11.5), the cleaning temperature is 65-75℃, and the cleaning time is 5-8 min; the most preferred scheme is: the volume ratio of HCl, H2O2, and H2O is 1:1:(9-10.5); the cleaning temperature is 65℃, and the cleaning time is 5 min. The main function of hydrochloric acid in the SC2 solution is to complex and dissolve the metal ion contaminants on the surface of the blockage. The chloride ions (Cl) provided by hydrochloric acid - ) and metal ions (such as Fe) 3+ Cu 2+ (etc.) form soluble chloride complexes, thereby effectively removing these metal ions; hydrogen peroxide can decompose under acidic conditions to generate highly oxidizing reactive oxygen species, and can also prevent dissolved metal ions from redepositing onto the cartridge surface; hydrochloric acid and hydrogen peroxide can chemically strip particles attached to the cartridge surface, especially particles that are chemically bonded to the surface.

[0025] (6) QDR cleaning: Clean with room temperature ultrapure water, including spraying, bubbling, rapid drainage and overflow; cleaning time is 4-6 minutes; the function of QDR is the same as that of HQDR, and will not be described in detail here.

[0026] (7) Spin-drying: Dry the stopper under centrifugal rotation at a speed of 500-2300 r / min; dry at a temperature of 30-50℃, more preferably 40-50℃, and most preferably 50℃; dry for 5-8 min, and most preferably 7 min.

[0027] The cleaning process for removing dirt from the edge of a chip jammer is described below with examples, and should not be construed as a limitation on the scope of protection of this invention. Example 1

[0028] A turnover PP stopper was used as the experimental stopper, and a cleaned silicon carbide substrate was used as the experimental wafer.

[0029] First, the cartridges were ultrasonically washed with ultrapure water. The cartridges were completely immersed in ultrapure water for 15 minutes at a temperature of 70°C and an ultrasonic frequency of 40 kHz. Next, the cartridges were immersed in an organic solution of FMES:NMP:MDEA:Na2SiO3:PVP:fatty alcohol polyoxyethylene ether:H2O = 3:12:4:2:0.75:4:74.25 at 38°C for 15 minutes at an ultrasonic frequency of 40 kHz. The surfactant compound effectively removed wax and some inorganic matter from the surface of the cartridges, and the ultrasonic treatment accelerated the removal of organic matter from the surface. The cartridges were then subjected to HQDR (High-Quality Cleaning) at 70°C for 8 minutes at 40 kHz to remove stubborn impurities and residual cleaning solution from the wafer surface. Afterward, the cartridges were wiped and brushed with cleanroom swabs equipped with polyester lint-free cloths. Continuous water spraying was used throughout the process to accelerate the removal of organic and inorganic particles. The cartridges were further treated with SC2 (HCl, H2O2, and H2O in a volume ratio of 1:1:10, at 65°C for 5 minutes), followed by QDR (quick-drying) for 5 minutes. This process primarily aims to generate soluble ionic complexes and remove alkali metal ions and metal hydroxides. Finally, the cartridges were spin-dried at 50°C for 7 minutes at 2000 rpm.

[0030] After the cartridge is spun dry, an edge contamination test is performed on the wafer after standard cleaning. The test method is as follows: the surface particle size of the wafer is first tested with Candela 8520, then placed in the cleaned cartridge, and then the surface particle size is tested again with Candela 8520 to compare the contamination of the wafer edge. The specific implementation is as follows: First, the particle size of 24 wafers is tested (see...). Figure 1 and Figure 2 (1) Prepare for use; then conduct experiments in three groups, with 8 randomly selected wafers in each group evenly placed in the test insert for 5 minutes; then test the particle size of 24 wafers; compare the edge contamination of the wafers before and after the experiment.

[0031] Following the implemented method, after cleaning, particles >0.2μm at the wafer edge (using Candela 8520 equipment) showed no aggregation or increase, resulting in a 100% pass rate. (See attached image.) Figure 3 and Figure 4 . Example 2

[0032] A turnover PP stopper was used as the experimental stopper, and a cleaned silicon carbide substrate was used as the experimental wafer.

[0033] First, the cartridges were ultrasonically washed with ultrapure water. The cartridges were completely immersed in ultrapure water for 10 minutes at a temperature of 75°C and an ultrasonic frequency of 40 kHz. Next, the cartridges were immersed in an organic solution of FMES:NMP:MDEA:Na2SiO3:PVP:fatty alcohol polyoxyethylene ether:H2O = 4:13:4:2:1:4:72 at 40°C for 15 minutes at an ultrasonic frequency of 40 kHz. The surfactant compound effectively removed wax and some inorganic matter from the surface of the cartridges, and the ultrasonic treatment accelerated the removal of organic matter from the surface. The cartridges were then subjected to HQDR (High-Quality Cleaning) at 70°C for 10 minutes at 40 kHz to remove stubborn impurities and residual cleaning solution from the wafer surface. Afterward, the cartridges were wiped and brushed with cleanroom swabs equipped with polyester lint-free cloths. Continuous water spraying was used throughout the process to accelerate the removal of organic and inorganic particles. The cartridges were further treated with SC2 (HCl, H2O2, and H2O in a volume ratio of 1:1:10, at 68°C for 5 minutes); followed by QDR (Quick Drying) for 5 minutes, primarily to generate soluble ionic complexes and remove alkali metal ions and metal hydroxides. Finally, the cartridges were spin-dried at 50°C for 7 minutes at 2000 rpm.

[0034] After the cartridge is spun dry, an edge contamination test is performed on the wafer after standard cleaning. The test method is as follows: the surface particle size of the wafer is first tested with Candela 8520, then placed in the cleaned cartridge, and then the surface particle size is tested again with Candela 8520 to compare the contamination of the wafer edge. The specific implementation is as follows: First, the particle size of 24 wafers is tested (see...). Figure 1 and Figure 2 (1) Prepare for use; then conduct experiments in three groups, with 8 randomly selected wafers in each group evenly placed in the test insert for 5 minutes; then test the particle size of 24 wafers; compare the edge contamination of the wafers before and after the experiment.

[0035] Following the implemented method, after cleaning, particles >0.2μm at the wafer edge (using Candela 8520 equipment) showed no aggregation or increase, resulting in a pass rate of 98.2%. (See [link to relevant documentation]). Figure 5 and Figure 6 .

[0036] Standard cleaning method: The cartridge was immersed in pure water and sonicated for 30 minutes at a temperature of 75°C and a frequency of 40 kHz. The cartridge was then subjected to HQDR treatment at a temperature of 70°C for 10 minutes at a frequency of 40 kHz. The cartridge was then spun dry at a temperature of 50°C for 7 minutes at a speed of 2000 rpm.

[0037] Following the implemented method, after cleaning, particles >0.2μm at the wafer edge (using Candela 8520 equipment) showed no aggregation or increase, resulting in a pass rate of 54.6%. (See attached image.) Figures 7-10 .

[0038] As can be seen from the above, the wafer pass rate is only 54.6% after using the conventional cassette cleaning technology; while after using the cassette cleaning process of the present invention, the wafer pass rate is 98.2%-100%, with an average of 99.1%, which is 44.5% higher than the wafer pass rate of conventional cleaning, and the cleaning effect is very significant.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cleaning process for removing edge contamination from a wafer carrier, comprising: The method comprises the following steps: (1) ultrapure water ultrasonic washing: completely immerse the cartridge in ultrapure water for 5-15 min, the immersion temperature is 70-80℃, and the ultrasonic frequency is 25-55 KHz; (2) cleaning with a compounded organic solution: completely immerse the cartridge in the compounded organic solution, and clean by ultrasonic from the bottom; (3) HQDR cleaning: clean with heated ultrapure water, including spraying, bubbling, fast draining and overflow; the cleaning temperature is 60-75℃, and the cleaning time is 4-20 min; (4) mechanical scrubbing: use a dust-free purified cotton swab / brush to scrub the gaps of the cartridge, and spray water at the same time; (5) SC2 cleaning: the cleaning reagent comprises HCL, H2O2 and H2O; the cleaning temperature is 60-80℃, and the cleaning time is 5-10 min; (6) QDR cleaning: clean with room temperature ultrapure water, including spraying, bubbling, fast draining and overflow; the cleaning time is 4-6 min; (7) spin-drying: dry the cartridge in a centrifugal rotation state, the drying temperature is 30-50℃, the drying time is 5-8 min, and the centrifugal rotation speed is 500-2300 r / min.

2. The cleaning process of claim 1, wherein, The ultrapure water ultrasonic washing time in the step (1) is 10-15 min; the immersion temperature is 70-75℃, and the ultrasonic frequency is 30-45 KHz.

3. The cleaning process of claim 2, wherein, The ultrapure water ultrasonic washing time is 15 min; the immersion temperature is 70℃, and the ultrasonic frequency is 40 KHz.

4. The cleaning process of claim 1, wherein, The compounded organic solution in the step (2) is composed of water and industrial-grade fatty acid methyl ester ethoxylate sulfonate, N-methyl pyrrolidone, N-methyl diethanolamine, sodium silicate, polyvinyl pyrrolidone and fatty alcohol polyoxyethylene ether; the mass percentages of the fatty acid methyl ester ethoxylate sulfonate, N-methyl pyrrolidone, N-methyl diethanolamine, sodium silicate, polyvinyl pyrrolidone and fatty alcohol polyoxyethylene ether are 2%-5%, 10%-15%, 3%-5%, 1%-3%, 0.5%-1% and 2%-5% respectively, and the water makes up to 100%; the cleaning time is 10-20 min, the cleaning temperature is 25-55℃, and the ultrasonic frequency is 25-55 KHz.

5. The cleaning process of claim 4, wherein the cleaning process is performed by a cleaning machine. The mass percentages of the fatty acid methyl ester ethoxylate sulfonate, N-methyl pyrrolidone, N-methyl diethanolamine, sodium silicate, polyvinyl pyrrolidone, fatty alcohol polyoxyethylene ether and water are 3%, 12%, 4%, 2%, 0.75%, 4% and 74.25% respectively; the cleaning time is 15 min, the cleaning temperature is 38℃, and the ultrasonic frequency is 40 KHz.

6. The cleaning process of claim 1, wherein, The cleaning temperature in the step (3) is 65-75℃, and the cleaning time is 5-10 min.

7. The cleaning process of claim 6, wherein the cleaning process is performed by a cleaning machine. The cleaning temperature in the step (3) is 70℃, and the cleaning time is 8 min.

8. The cleaning process of claim 1, wherein, The cotton swab / brush in the step (4) is one or more of polyester dust-free cloth head, sponge head and polyvinyl alcohol.

9. The cleaning process of claim 1, wherein, The mass concentration of the HCL reagent in the step (5) is 36%-38%, the mass concentration of the H2O2 reagent is 30%-32%, the volume ratio of HCL, H2O2 and H2O is 1:(0.5-2.5):(7.5-12.5), the cleaning temperature is 65-75 DEG C, and the cleaning time is 5-8 min.

10. The cleaning process of claim 9, wherein the cleaning process is performed by a cleaning machine. The volume ratio of HCL, H2O2 and H2O in the step (5) is 1:1:(9-10.5), the cleaning temperature is 65 DEG C, and the cleaning time is 5 min.

Images