Silicon leftover material cleaning agent as well as preparation method and use method thereof

Abstract

The invention discloses a silicon leftover material cleaning agent as well as a preparation method and a use method thereof, and belongs to the technical field of silicon wafer processing. The cleaning agent comprises the following components in parts by weight: 20-40 parts of liquid caustic soda, 1-5 parts of a surfactant, 1-5 parts of a glue remover, 1-5 parts of a dispersing agent and the balance of water, wherein the total parts by weight are 100. The liquid caustic soda, the multiple surfactants, the degumming agent, the dispersing agent and the moisture absorbent are combined according to a specific ratio, so that the decontamination capability and the cleaning effect can be improved, and the surface of the silicon leftover material is ensured to be clean; wiping times can be reduced, working intensity is reduced, and working efficiency is improved; components of the cleaning agent are nontoxic and harmless, and the operation safety in the cleaning process is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of silicon wafer processing. Specifically, it relates to a silicon corner waste cleaning agent, a preparation method thereof, and a usage method thereof. Background Art

[0002] During the cutting process of single-crystal silicon wafers, the thick wafers at both ends are usually referred to as "head and tail thick wafers" or "head and tail corner wastes". Due to the limitations of the cutting process, these wafers are usually thicker than the middle silicon wafers and may have some quality problems, such as surface defects or crystal defects. Some head and tail wafers can be recycled through subsequent processing, such as remelting and casting to make new silicon ingots. Usually, there are some impurity substances remaining on the surface of the thick wafers, which hinder their remelting, such as: metal chips or silicon chips generated during the cutting process, residual glue of marking information, and cutting fluid used during the cutting process.

[0003] Currently, compared with other corner wastes (such as sawn silicon materials), before mechanical batch cleaning, the thick wafers need to be manually wiped first. If there is stubborn glue stain on the surface, some degreasing agents need to be sprayed appropriately and then wiped; for difficult-to-clean corners or crevices, soft brushes need to be used to scrub to ensure thorough cleaning. After wiping, check the surface of the thick wafers again to confirm whether all residues have been removed. Otherwise, repeat the wiping process until the surface reaches a satisfactory cleanliness. During the whole process, the operator needs to wear protective gloves and masks, keep the tools clean, and take anti-static measures to ensure the safety and cleanliness of the thick wafers. During the manual wiping process, there are the following disadvantages: (1) Uneven cleaning: Manual wiping depends on the skills and experience of the operator, which may lead to inconsistent cleaning effects. Some areas may be cleaned relatively cleanly, while other areas may still have dirt residues. (2) Low efficiency: Manual wiping usually requires more time and labor, especially when dealing with large quantities or complex surfaces, and the efficiency is much lower than that of automated chemical agent cleaning. (3) Unable to remove stubborn dirt: Some stubborn pollutants (such as grease, glue, etc.) may require specific chemical agents to be effectively removed, and manual wiping may not be able to completely remove these dirt. (4) High labor intensity: Manual wiping requires high physical strength and endurance, and long-term cleaning work may cause fatigue of the operator, thus affecting the cleaning effect and work safety. (5) Difficulty in standardization: It is difficult to unify the cleaning standards for manual wiping. Different operators may have different cleaning methods and intensities, resulting in differences in the final results. Summary of the Invention

[0004] The main purpose of the present application is to provide a silicon corner waste cleaning agent, a preparation method thereof, and a usage method thereof, so as to solve the problems of low efficiency, long time, and poor effect in removing pollutants by the silicon corner waste cleaning agent in the prior art.

[0005] To achieve the above object, according to one aspect of the present application, a silicon scrap cleaning agent is provided. The cleaning agent comprises the following components in parts by weight:

[0006] 20 - 40 parts of liquid caustic, 1 - 5 parts of surfactant, 1 - 5 parts of degumming agent, 1 - 5 parts of dispersant, and the balance is water, with a total of 100 parts; wherein, the concentration of the liquid caustic is 25wt% - 32wt%.

[0007] Further, the parts by weight of the liquid caustic are 30 - 40 parts, the parts by weight of the surfactant are 2 - 3 parts, the parts by weight of the degumming agent are 2 - 3 parts, the parts by weight of the dispersant are 1 - 2 parts, and the balance is pure water, with a total of 100 parts.

[0008] Further, the components of the cleaning agent further comprise 2 - 8 parts of a moisture absorbent.

[0009] Further, the components of the cleaning agent further comprise 4 - 5 parts of a moisture absorbent.

[0010] Further, the liquid caustic is an inorganic base solution.

[0011] Further, the inorganic base solution is a potassium hydroxide solution and / or a sodium hydroxide solution.

[0012] Further, the surface tension of the surfactant is less than 50 N / m.

[0013] Further, the surfactant is selected from polyoxyethylene ether nonionic surfactants.

[0014] Further, the surfactant is selected from at least one of isodecyl alcohol polyoxyethylene ether, lauryl alcohol polyoxyethylene ether, lauryl alcohol polyoxyethylene ether - 4, and isotridecyl alcohol polyoxyethylene ether.

[0015] Further, the degumming agent is selected from at least one of triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, and 4 - methoxycyclohexanone.

[0016] Further, the dispersant is selected from at least one of sodium polyacrylate, alkylphenol polyoxyethylene ether, and tridecanol polyether - 4.

[0017] Further, the moisture absorbent is selected from polyethylene glycol.

[0018] Further, the weight - average molecular weight of the polyethylene glycol is 200 - 1000; more preferably 400 - 600.

[0019] According to the second aspect of the present application, a preparation method of the above - mentioned silicon thick - wafer cleaning agent is provided, comprising the following steps: first, add the liquid caustic to a part of water and perform the first stirring cycle; then add the surfactant, degumming agent, dispersant, optional moisture absorbent, and the remaining part of water, and perform the second stirring cycle to obtain the silicon thick - wafer cleaning agent after mixing.

[0020] Further, the dropping rate of the liquid caustic soda is (1.9 - 2.1) L / s.

[0021] Further, the rotation speed of the first stirring cycle is 100 - 300 rpm, and the time is 30 - 50 min.

[0022] Further, the rotation speed of the second stirring cycle is 100 - 300 rpm, and the time is 1 - 2 h.

[0023] According to the third aspect of the present application, there is provided the above-mentioned method for using the silicon corner waste cleaning agent. The silicon corner waste is soaked in the cleaning agent at a soaking temperature of 30 - 50 °C for 40 - 60 min; after soaking, it is rinsed with pure water; wherein, the weight ratio of the silicon corner waste to the cleaning agent is 1000:(15 - 25).

[0024] Applying the technical solution of the present application, there is provided a silicon corner waste cleaning agent. Through the specific proportion combination of liquid caustic soda, various surfactants, degumming agents, dispersants and optional moisture absorbents, the decontamination ability and cleaning effect can be improved, ensuring the cleanliness of the surface of the silicon corner waste; the wiping times can be reduced, the working intensity can be reduced, and the working efficiency can be improved; the components of the cleaning agent are non-toxic and harmless, ensuring the operation safety of the cleaning process. Detailed Embodiments

[0025] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the embodiments.

[0026] In the prior art, during the production and processing of silicon material corner wastes such as silicon thick wafers, various pollutants are easily attached, such as oil stains and glue residues. Existing cleaning agents may not be able to effectively remove these pollutants; the cleaning effect of the cleaning agent is poor and uneven; for example, some areas of the silicon thick wafer may be cleaned relatively clean, while some areas may have dirt residues; and manual wiping requires more time and manpower, especially when dealing with large quantities or complex surfaces; some stubborn pollutants such as grease or glue are not easy to remove; long-term manual wiping will increase the labor intensity.

[0027] Therefore, the present application provides a silicon corner waste cleaning agent, which includes the following components in parts by weight:

[0028] 20 - 40 parts of liquid caustic soda, 1 - 5 parts of surfactant, 1 - 5 parts of degumming agent, 1 - 5 parts of dispersant, and the balance is water, totaling 100 parts; wherein, the concentration of the liquid caustic soda is 25 wt% - 32 wt%.

[0029] In the cleaning agent of this application, liquid caustic soda is selected and its proportion is controlled at 20-40 parts, which can better react with the residual silicon powder on the surface of silicon scraps, and then effectively remove the residual silicon powder from the surface of the thick sheet; adding a surfactant and controlling its proportion at 1-5 parts can significantly reduce the surface tension of the liquid, making the liquid easier to wet and penetrate the solid surface, and through the interaction of its hydrophilic and hydrophobic parts, it can effectively wrap and disperse the dirt, grease and other pollutants on the surface of silicon scraps, especially remove the stains in the tiny gaps of the thick sheet, which makes the dirt suspended in water and thus easier to be wiped or rinsed off. If the proportion of the surfactant is too high, stratification will occur, and the proportion needs to be controlled below 5 parts; adding a degumming agent and controlling its proportion at 1-5 parts can better peel and remove the residual glue from the surface of silicon scraps, facilitating cleaning; there is a synergistic effect between liquid caustic soda and the degumming agent, and long-term soaking can soften the residual glue, making the glue stain easier to be removed; adding a dispersant and controlling its proportion at 1-5 parts can better disperse the stains removed from the surface of silicon scraps in the liquid, preventing them from precipitating or re-adsorbing, facilitating cleaning.

[0030] In the above cleaning agent formula of the present application, the weight parts of liquid caustic soda are any value among 20, 25, 30, 35, 40 or the range value between any two of them; the mass concentration of liquid caustic soda is 25% - 32%; for example, 25%, 28%, 30%, 32%. When the weight ratio of liquid caustic soda is certain, using liquid caustic soda with this concentration can fully react with the residual silicon slag on the surface of silicon offcuts, improve the effect of removing silicon slag, and will not affect the quality of the silicon material itself. When the proportion of liquid caustic soda is less than 20 parts, it cannot fully react with the residual silicon slag on the surface of silicon offcuts, and thus cannot effectively remove the residual silicon slag, which will reduce the decontamination effect. When the proportion of liquid caustic soda exceeds 40 parts, although it can fully react with the residual silicon slag on the surface of silicon offcuts, it may affect the quality of the silicon material itself, and will also affect the performance of other components, even reduce the synergistic effect with other components, and then reduce the overall cleaning effect on the surface of silicon offcuts. The weight parts of the surfactant are any value among 1, 2, 3, 4, 5 or the range value between any two of them; when the proportion is less than 1 part, it cannot effectively reduce the surface tension of the cleaning agent liquid, the cleaning agent liquid will not fully wet and penetrate the surface of silicon offcuts, cannot effectively wrap and disperse the dirt, grease and other pollutants on the surface of thick wafers, and cannot effectively remove the pollutants, which will increase the difficulty of later wiping; when the proportion exceeds 5 parts, it will cause excessive foaming of the cleaner, may reduce the cleaning effect, and will also affect the synergistic effect with other components, will increase the later manual wiping effect, and increase unnecessary costs. The weight parts of the degumming agent are any value among 1, 2, 3, 4, 5 or the range value between any two of them; when the proportion is less than 1 part, it cannot effectively peel the residual glue on the surface of silicon offcuts and is not easy to clean. When the proportion exceeds 5 parts, it may affect the properties of the silicon material itself, will reduce the performance of other components, reduce the synergistic effect with other components, may overreact with the glue, making it more difficult to remove the glue on the surface of thick wafers, will increase the later manual wiping difficulty, and will also increase costs. The weight parts of the dispersant are any value among 1, 2, 3, 4, 5 or the range value between any two of them; when the proportion is less than 1 part, it cannot effectively disperse and stabilize the dirt removed from the surface of thick wafers in the cleaning agent solution, and cannot effectively prevent these dirt from precipitating or re-adsorbing. When the proportion exceeds 5 parts, it will affect the properties of other components and thus affect the synergistic effect with other components. Excessive use will affect the overall stability of the cleaning agent liquid, may cause stratification and precipitation phenomena, and will also increase costs and increase the later manual wiping efficiency. Therefore, only by controlling the above components within a reasonable range can the components play a better synergistic effect, enhance the cleaning effect of silicon offcuts and have no side effects; the components selected in the present application can minimize the irritation and toxicity to the human body and ensure safe operation during the cleaning process.

[0031] In some embodiments, the weight portion of liquid caustic soda is 30 to 40 parts, the weight portion of the surfactant is 2 to 3 parts, the weight portion of the glue remover is 2 to 3 parts, the weight portion of the dispersant is 1 to 2 parts, the weight portion of the moisture absorbent is 4 to 5 parts, and the balance is pure water, totaling 100 parts. By adopting the component ratios in the above cleaning agent, each component can play a better synergistic effect, further improving the glue stain removal rate, such as more than 80%, and further improving the surface light reflectivity of the silicon scraps, such as more than 72%. By improving the decontamination ability, subsequent manual wiping becomes easier, reducing the manual labor intensity. For example, the manual wiping time can be shortened to 1 / 3 of the traditional cleaning time.

[0032] In some embodiments, the weight portion of liquid caustic soda is 30 to 40 parts, the weight portion of the surfactant is 2 to 3 parts, the weight portion of the glue remover is 2 to 3 parts, the weight portion of the dispersant is 1 to 2 parts, the weight portion of the moisture absorbent is 4 to 5 parts, and the balance is pure water, totaling 100 parts; wherein, the liquid caustic soda is sodium hydroxide solution and / or potassium hydroxide solution, with a concentration of 28wt% to 32wt%; the surfactant is isomeric decanol polyoxyethylene ether (CAS: 61827-42-7) and / or lauryl alcohol polyoxyethylene ether (CAS: 9002-92-0); the glue remover is diethylene glycol monobutyl ether (CAS: 112-34-5) and / or triethylene glycol monobutyl ether (CAS: 142-18-7); the dispersant is sodium polyacrylate (CAS: 9003-04-7) and / or alkylphenol polyoxyethylene ether (CAS: 9016-45-9); the moisture absorbent is PEG400 and / or PEG600. By further optimizing the component ratios and component types, the decontamination effect is further improved, the surface light reflectivity is 72% to 83%, the glue stain removal rate is 72% to 88%, and the manual wiping time is 120 to 125 min.

[0033] In some embodiments, there are 30 parts of liquid caustic soda (sodium hydroxide solution, concentration 30wt%), 2 parts of surfactant: isomeric decanol polyoxyethylene ether (CAS: 61827-42-7), 3 parts of glue remover: triethylene glycol monobutyl ether (CAS: 142-18-7), 2 parts of dispersant: sodium polyacrylate (CAS: 9003-04-7), 4 parts of moisture absorbent: polyethylene glycol (weight average molecular weight 400, i.e., PEG400), and the balance is pure water, totaling 100 parts. The surface light reflectivity is 72%, the glue stain removal rate is 88%, and the manual wiping time is 120 min.

[0034] In some embodiments, 40 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), 3 parts of surfactant: lauryl alcohol polyoxyethylene ether (CAS: 9002-92-0), 2 parts of degumming agent: diethylene glycol monobutyl ether (CAS: 112-34-5), 1 part of dispersant: alkylphenol polyoxyethylene ether (CAS: 9016-45-9), 5 parts of moisture absorbent: polyethylene glycol (weight average molecular weight 600, i.e., PEG 600), and the balance is pure water, with a total of 100 parts. The surface light reflectance is 83%, the gum stain removal rate is 72%, and the manual wiping time is 120 - 125 min.

[0035] In some embodiments, the silicon scrap cleaning agent composition further includes a moisture absorbent, with a proportion of 2 - 8 parts, and further preferably 4 - 5 parts. The weight parts of the moisture absorbent are any value among 2, 3, 4, 5, 6, 7, 8 or the range value between any two of them; when less than 2 parts, it cannot effectively prevent the volatilization of certain components in the cleaning agent such as the degumming agent; when the proportion exceeds 8 parts, it may reduce its moisture absorption effect and increase the cost; adding a moisture absorbent can prevent stratification caused by water evaporation during long-term storage, and it can be added appropriately according to the storage time.

[0036] In some embodiments, the liquid caustic soda is selected as an inorganic base solution; for example, potassium hydroxide solution and / or sodium hydroxide solution are selected; by selecting the above types of liquid caustic soda, the reaction efficiency with the residual silicon slag of the silicon scrap can be enhanced, and the usage amount of the liquid caustic soda can be reduced.

[0037] In some embodiments, the surface tension of the surfactant is less than 50 N / m. By controlling the surface tension within the above range, the surfactant has a suitable effect, thereby ensuring a better cleaning effect. For example, at least one of isodecyl alcohol polyoxyethylene ether (CAS: 61827-42-7), lauryl alcohol polyoxyethylene ether (CAS: 9002-92-0), lauryl alcohol polyoxyethylene ether-4 (AEO-3, CAS: 68439-50-9), and isotridecyl alcohol polyoxyethylene ether (CAS: 9043-30-5) can be selected. The above specific types of surfactants can make the cleaning agent liquid fully wet and penetrate the surface of the thick sheet, can effectively wrap and disperse the dirt, grease, and other pollutants on the surface of the thick sheet, are easy to clean, and reduce the subsequent manual wiping time.

[0038] In some embodiments, the degumming agent is selected from at least one of triethylene glycol monobutyl ether (CAS: 142-18-7), diethylene glycol monobutyl ether (CAS: 112-34-5), tetraethylene glycol monobutyl ether (CAS: 143-22-6), and 4-methoxycyclohexanone (CAS: 13482-23-0). The above specific degumming agents can fully peel off the residual glue on the surface of the thick sheet, improve the degumming effect, are easy to clean, and reduce the subsequent manual wiping intensity.

[0039] In some embodiments, the dispersant is selected from at least one of sodium polyacrylate (CAS: 9003-04-7), alkylphenol polyoxyethylene ether (CAS: 9016-45-9), and tridecanol polyether-4 (CAS: 69011-36-5). The above-mentioned specific dispersant can better disperse and stabilize the removed stains in the cleaning agent solution, effectively preventing the stains from precipitating or re-adsorbing.

[0040] In some embodiments, the humectant is selected from polyethylene glycol. For example, the polyethylene glycol with a weight average molecular weight of 200 to 1000 can be selected; further, it can be 400 to 600, such as PEG200, PEG400, PEG600, PEG800, and PEG1000. The humectant with this molecular weight can effectively reduce the volatility of the components in the cleaning agent, such as preventing the volatilization loss of the adhesive remover, ensuring that each component can fully play its role, ensuring good solubility of each component, and ensuring good synergistic effects among the components.

[0041] According to the second aspect of the present application, a method for preparing the above-mentioned silicon scrap cleaning agent is provided, including the following steps: First, add liquid caustic soda to a part of water and perform the first stirring cycle; then add a surfactant, an adhesive remover, a dispersant, an optional humectant, and the remaining part of water, and perform the second stirring cycle. After mixing, a silicon thick sheet cleaning agent is obtained.

[0042] In some embodiments, 10 parts of water and liquid caustic soda can be added first and fully mixed, and the dropping rate of the liquid caustic soda is controlled to be (1.9 - 2.1) L / s, such as 2 L / s, to avoid violent reactions; the rotation speed of the first stirring cycle is 100 - 300 rpm, and the time is 30 - 50 min; the rotation speed of the second stirring cycle is 100 - 300 rpm, and the time is 1 - 2 h; through two-step mixing and appropriate stirring and mixing speeds, each component can be fully dissolved and mixed to obtain a cleaning agent solution with better quality.

[0043] According to the third aspect of the present application, a method for using the above-mentioned silicon scrap cleaning agent is provided. The silicon scrap is completely immersed in the cleaning agent, and the soaking temperature and time are set according to the degree of dirt and the concentration of the cleaning agent. For example, the temperature is 30 - 50 °C, and the soaking time is 40 - 60 min. Ultrasonic waves can be appropriately increased during the soaking process to enhance the cleaning effect. After soaking, it is rinsed with pure water; among them, the weight ratio of the silicon scrap to the cleaning agent is 1000:(15 - 25); for example, 20 kg of the cleaning agent is used for 1 ton of silicon scrap, and it is soaked at 45 °C for 50 min.

[0044] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0045] All raw materials used in the embodiments of the present application are existing technologies and can be purchased commercially.

[0046] Example 1

[0047] The silicon scrap cleaning agent comprises the following components in parts by weight: 30 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), surfactant: isodecyl alcohol polyoxyethylene ether (CAS: 61827-42-7) 2 parts, degumming agent: triethylene glycol monobutyl ether (CAS: 142-18-7) 3 parts, dispersant: sodium polyacrylate (CAS: 9003-04-7) 2 parts, moisture absorbent: polyethylene glycol (weight average molecular weight 400, i.e., PEG400) 4 parts, pure water: the balance, totaling 100 parts.

[0048] Preparation method of the silicon scrap cleaning agent: Add 10 parts of pure water into a stirring barrel, add the weighed liquid caustic soda into an appropriate amount of pure water, stir evenly to fully dissolve it, and stir and circulate at 200 rpm for 40 min; pay attention to controlling the addition speed of the liquid caustic soda at 2 L / s to avoid violent reactions; uniformly add the surfactant, degumming agent, dispersant, moisture absorbent, and the remaining pure water; stir until the solution is uniform, and then stir and circulate at 200 rpm for 1.5 h to obtain the cleaning agent.

[0049] Example 2

[0050] The difference between Example 2 and Example 1 lies in the different cleaning agent formulations;

[0051] Silicon scrap cleaning agent formulation: 40 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), surfactant: lauryl alcohol polyoxyethylene ether (CAS: 9002-92-0) 3 parts, degumming agent: diethylene glycol monobutyl ether (CAS: 112-34-5) 2 parts, dispersant: alkylphenol polyoxyethylene ether (CAS: 9016-45-9) 1 part, moisture absorbent: polyethylene glycol (weight average molecular weight 600, i.e., PEG 600) 5 parts, pure water: the balance, totaling 100 parts.

[0052] Example 3

[0053] The difference between Example 3 and Example 1 lies in the different cleaning agent formulations;

[0054] Silicon scrap cleaning agent formulation: 25 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), surfactant: AEO-3 (CAS: 68439-50-9) 1 part, isotridecyl alcohol polyoxyethylene ether (CAS: 9043-30-5) 1 part, degumming agent: tetraethylene glycol monobutyl ether (CAS: 143-22-6) 4 parts, dispersant: tridecanol polyether-4 (CAS: 69011-36-5) 2 parts, moisture absorbent: polyethylene glycol (weight average molecular weight 800, i.e., PEG 800) 3 parts, pure water: the balance, totaling 100 parts.

[0055] Example 4

[0056] Example 4 is different from Example 1 in that the cleaner formulation is different;

[0057] Silicon scrap cleaning agent formulation: 35 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), surfactant: isodecyl alcohol polyoxyethylene ether (CAS: 61827-42-7) 2 parts, lauryl alcohol polyoxyethylene ether (CAS: 9002-92-0) 2 parts, degumming agent: 4-methoxycyclohexanone (CAS: 13482-23-0) 1 part, dispersant: sodium polyacrylate (CAS: 9003-04-7) 3 parts, moisture absorbent: polyethylene glycol (weight average molecular weight 200, i.e., PEG 200) 6 parts, pure water: the balance, totaling 100 parts.

[0058] Example 5

[0059] Example 5 is different from Example 1 in that the cleaner formulation is different;

[0060] Silicon scrap cleaning agent formulation: 20 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), surfactant: AEO-3 (CAS: 68439-50-9) 5 parts, degumming agent: triethylene glycol monobutyl ether (CAS: 142-18-7) 1 part, diethylene glycol monobutyl ether (CAS: 112-34-5) 1 part, dispersant: alkylphenol polyoxyethylene ether (CAS: 9016-45-9) 1 part, moisture absorbent: polyethylene glycol (weight average molecular weight 1000, i.e., PEG 1000) 2 parts, pure water: the balance, totaling 100 parts.

[0061] Example 6

[0062] Example 6 is different from Example 1 in that the cleaner formulation is different;

[0063] Silicon scrap cleaning agent formulation: 30 parts of liquid caustic soda (sodium hydroxide solution, concentration 30 wt%), surfactant: isodecyl alcohol polyoxyethylene ether (CAS: 61827-42-7) 1 part, degumming agent: triethylene glycol monobutyl ether (CAS: 142-18-7) 5 parts, dispersant: sodium polyacrylate (CAS: 9003-04-7) 5 parts, moisture absorbent: polyethylene glycol (weight average molecular weight 200, i.e., PEG 200) 8 parts, pure water: the balance, totaling 100 parts.

[0064] Example 7

[0065] Example 7 is different from Example 1 in that the cleaning agent raw materials do not contain a moisture absorbent, and the balance is water, totaling 100 parts.

[0066] Example 8

[0067] Example 8 is different from Example 1 in that the sodium hydroxide solution is replaced with a potassium hydroxide solution with a concentration of 30 wt%.

[0068] Example 9

[0069] Example 9 is different from Example 1 in that the concentration of the sodium hydroxide solution is replaced with 28 wt%.

[0070] Example 10

[0071] Example 10 is different from Example 1 in that the concentration of the sodium hydroxide solution is replaced with 32 wt%.

[0072] Example 11

[0073] Example 11 is different from Example 1 in that the surfactant is replaced with lauryl alcohol polyoxyethylene ether (CAS: 9002-92-0).

[0074] Example 12

[0075] Example 12 is different from Example 1 in that the degumming agent is replaced with 4-methoxycyclohexanone (CAS: 13482-23-0).

[0076] Example 13

[0077] Example 13 is different from Example 1 in that the dispersant is replaced with tridecanol polyether-4 (CAS: 69011-36-5).

[0078] Comparative Example 1

[0079] Comparative Example 1 is different from Example 1 in that there are 15 parts of 30 wt% liquid caustic soda, and the balance is pure water, with a total of 100 parts.

[0080] Comparative Example 2

[0081] Comparative Example 2 is different from Example 1 in that there are 45 parts of 30 wt% liquid caustic soda, and the balance is pure water, with a total of 100 parts.

[0082] Comparative Example 3

[0083] Comparative Example 3 is different from Example 1 in that there are 0.5 parts of surfactant: isomeric decanol polyoxyethylene ether, and the balance is pure water, with a total of 100 parts.

[0084] Comparative Example 4

[0085] Comparative Example 4 is different from Example 1 in that there are 8 parts of surfactant: isomeric decanol polyoxyethylene ether, and the balance is pure water, with a total of 100 parts.

[0086] Comparative Example 5

[0087] The difference between Comparative Example 5 and Example 1 is that the degumming agent is 0.5 part of triethylene glycol monobutyl ether, and the balance is pure water, with a total of 100 parts.

[0088] Comparative Example 6

[0089] The difference between Comparative Example 6 and Example 1 is that the degumming agent is 8 parts of triethylene glycol monobutyl ether, and the balance is pure water, with a total of 100 parts.

[0090] Comparative Example 7

[0091] The difference between Comparative Example 7 and Example 1 is that the dispersant is 0.5 part of sodium polyacrylate, and the balance is pure water, with a total of 100 parts.

[0092] Comparative Example 8

[0093] The difference between Comparative Example 8 and Example 1 is that the dispersant is 8 parts of sodium polyacrylate, and the balance is pure water, with a total of 100 parts.

[0094] Comparative Example 9

[0095] Use pure water as the silicon offcut cleaner.

[0096] Comparative Example 10

[0097] Use a 30 wt% sodium hydroxide solution as the silicon offcut cleaner.

[0098] Verify the effects of the cleaners prepared in Examples 1 to 13 and Comparative Examples 1 to 10:

[0099] Put the silicon offcuts into the cleaning tank. For one ton of silicon offcuts (thick slices), use 20 kg of the agent, ensure that the thick slices are completely immersed in the cleaning agent, and soak at 45 °C for 50 min; after soaking, rinse the silicon offcuts in pure water.

[0100] Cleaning effect detection:

[0101] Surface light reflectivity: Use a British Rhopoint Novo shade DUO+ reflectometer, with an incident angle of 10° and a light source wavelength of 500 nm visible light. Randomly sample at the four corners and the center, and take the average of the reflectivities at 5 points. The higher the surface light reflectivity, the better the cleaning effect.

[0102] Gum stain removal rate: Take silicon offcuts with gum stains and mark them. Use a 1 cm × 1 cm transparent plastic grid to cover the gum stains, and count A as the total number of grids with a gum stain area ratio greater than or equal to 1 / 2. After the thick slice is cleaned, count B using the same method. The gum stain removal rate = (A - B) / A. Sample at least 10 portions and find the average value. The higher the gum stain removal rate, the better the cleaning effect.

[0103] Manual wiping time: After cleaning is completed, the remaining glue stains are manually screened and wiped again until the glue stains are invisible to the naked eye. The average wiping time per ton of thick sheets is counted, with the unit of min. The lower the manual wiping time, the better the cleaning effect.

[0104] Table 1

[0105]

[0106]

[0107] As can be seen from the cleaning effect test results in Table 1, the comprehensive cleaning effect of the silicon corner waste cleaners prepared in Examples 1-13 of the present application is significantly better than that of the cleaners prepared in Comparative Examples 1-10; the glue stain removal rate of the cleaner of the present application is increased by more than 5 times compared with pure water, and the highest is nearly about 15 times; the subsequent manual wiping time can be shortened to more than 1 / 3 of the original; the surface light reflectivity of the silicon corner waste after cleaning is increased to about 3-4 times.

[0108] The silicon corner waste cleaning agent provided by the present application combines liquid caustic soda, various surfactants, degumming agents, dispersants and optionally hygroscopic agents in a specific ratio, which significantly improves the decontamination ability and cleaning effect, ensuring the cleanliness of the surface of the silicon corner waste; it can reduce the number of wiping times, reduce the working intensity and improve the working efficiency; and the components of this cleaning agent are non-toxic and harmless, ensuring the operation safety of the cleaning process.

[0109] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those described herein.

[0110] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A silicon waste corner cleaner, characterized in that, The cleaning agent comprises the following components in parts by weight: 20 - 40 parts of liquid caustic, 1 - 5 parts of surfactant, 1 - 5 parts of degumming agent, 1 - 5 parts of dispersant, with the balance being water, totaling 100 parts; the concentration of the liquid caustic is 25wt% - 32wt%.

2. The silicon corner waste cleaner according to claim 1, characterized in that, The weight parts of the liquid caustic are 30 - 40 parts, the weight parts of the surfactant are 2 - 3 parts, the weight parts of the degumming agent are 2 - 3 parts, the weight parts of the dispersant are 1 - 2 parts, with the balance being pure water, totaling 100 parts.

3. The silicon corner waste cleaner according to claim 1 or 2, characterized in that The components of the cleaning agent further include 2 - 8 parts of moisture absorbent; preferably 4 - 5 parts; and / or, the liquid caustic is an inorganic base solution; the inorganic base solution is a potassium hydroxide solution and / or a sodium hydroxide solution.

4. The silicon corner waste cleaning agent according to any one of claims 1 to 3, characterized in that The surface tension of the surfactant is less than 50 N / m; and / or, the surfactant is selected from polyoxyethylene ether non - ionic surfactants; and / or, the surfactant is selected from at least one of isodecyl polyoxyethylene ether, lauryl polyoxyethylene ether, lauryl polyoxyethylene ether - 4, and isotridecyl polyoxyethylene ether.

5. The silicon corner waste cleaning agent according to any one of claims 1 to 4, characterized in that The degumming agent is selected from at least one of triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, and 4 - methoxycyclohexanone.

6. The silicon corner waste cleaning agent according to any one of claims 1 to 5, characterized in that The dispersant is selected from at least one of sodium polyacrylate, alkylphenol polyoxyethylene ether, and tridecanol polyether - 4.

7. The silicon corner waste cleaning agent according to any one of claims 3 to 6, characterized in that The moisture absorbent is selected from polyethylene glycol; preferably, the weight - average molecular weight of the polyethylene glycol is 200 - 1000; more preferably 400 - 600.

8. A method for preparing the silicon waste corner cleaner according to any one of claims 1 to 7, characterized in that, The preparation method comprises the following steps: first, add the liquid caustic to a part of water and conduct the first stirring cycle; then add the surfactant, the degumming agent, the dispersant, the optional moisture absorbent, and the remaining part of water, and conduct the second stirring cycle. After mixing, the silicon corner waste cleaning agent is obtained.

9. The preparation method of the silicon corner waste cleaning agent according to claim 8, characterized in that, The dropping rate of the liquid caustic is (1.9 - 2.1) L / s; and / or, the rotation speed of the first stirring cycle is 100 - 300 rpm, and the time is 30 - 50 min; and / or, the rotation speed of the second stirring cycle is 100 - 300 rpm, and the time is 1 - 2 h.

10. A method for using the silicon scrap cleaning agent according to any one of claims 1 to 7, characterized in that, Soak the silicon corner waste in the cleaning agent at an immersion temperature of 30 - 50 °C for 40 - 60 min; after soaking, rinse with pure water; wherein, the weight ratio of the silicon corner waste to the cleaning agent is 1000:(15 - 25).

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