Single crystal machine cleaning material cleaning process

Abstract

The invention discloses a single crystal machine cleaning material cleaning process which specifically comprises the following operation steps: sending a machine cleaning material to a silicon material workshop, and after the silicon material workshop receives the machine cleaning material, firstly putting the machine cleaning material into a stirrer for stirring and cleaning; taking out the raw materials, carrying out sorting and magnetic separation, carrying out alkali washing after sorting is completed, and removing substances such as oil stains and the like in the machine cleaning materials by using high-purity composite alkali; carrying out ultrasonic water washing until the pH value of water reaches neutral, then soaking with HF acid, carrying out water washing ultrasonic treatment, and then cleaning with HF + HNO3 mixed acid; after cleaning is completed, water washing, ultrasonic treatment and drying are conducted, and packaging and warehousing are conducted. According to the single crystal machine cleaning material cleaning process, a special machine cleaning material cleaning scheme is designed, the machine cleaning material can be rapidly cleaned, it can be guaranteed that the quality of the machine cleaning material is not abnormal, the purpose of recycling the machine cleaning material is achieved, the quality of products produced after the machine cleaning material is recycled is improved by 10%, and the yield is improved by 5%.

Description

Technical Field

[0001] This invention relates to the field of cleaning technology for cleaning materials, and in particular to a cleaning process for cleaning materials from single crystals. Background Technology

[0002] The single-crystal cleaning process is a method for cleaning silicon material from the equipment. This material typically contains a significant amount of silicon sludge, especially after machining. The surface of the cleaned material often has severe silicon sludge buildup, requiring cleaning before reuse. Currently, the single-crystal industry faces overcapacity. To remain competitive, companies continuously explore cost-reduction and efficiency-enhancing projects, leading to the reuse of cleaned material for crystal pulling. However, this reuse often results in quality and pulling anomalies, leading to low yields and unsold products, ultimately increasing silicon costs. With continuous technological advancements, the requirements for single-crystal cleaning processes are becoming increasingly stringent.

[0003] Existing cleaning materials have certain drawbacks when reused. The surface of the cleaning materials is heavily coated with silicon sludge. If not cleaned properly, it will cause many abnormal crystal pulling quality during reuse. For example, due to impurities not being cleaned, the crystal pulling process will frequently break, and the minority carrier lifetime of the produced crystal rods will not meet the requirements of normal shipment products. In the end, they can only be sold externally or purified, which will increase the cost of silicon material and bring certain adverse effects to people's use. To this end, we propose a single crystal cleaning material cleaning process. Summary of the Invention

[0004] Technical problem to be solved: In view of the shortcomings of the existing technology, the present invention provides a single crystal cleaning process and designs a special cleaning solution for cleaning materials, which can achieve rapid cleaning of cleaning materials and ensure that the quality of cleaning materials is not abnormal, so as to achieve the purpose of recycling cleaning materials and effectively solve the problems in the background technology.

[0005] Technical Solution: To achieve the above objectives, the technical solution adopted by this invention is: a single-crystal cleaning process for cleaning materials, specifically including the following steps: S1: Silicon material removed from the machine tool after machining and collected in a centralized manner is called machine cleaning material; S2: The cleaning material is shipped to the silicon material workshop. After receiving the cleaning material, the silicon material workshop first places the cleaning material into a mixer, similar to a cement mixer. The mixer container is made of non-metallic material, and the cleaning material is stirred and cleaned. S3: After stirring, take out the raw material, sort and magnetically separate it, and then wash it with alkali. Use high-purity compound alkali to remove oil and other substances from the cleaning material. S4: Perform ultrasonic water washing until the pH value of the water reaches neutral, then soak in HF acid for a certain period of time, then perform water washing and ultrasonic washing again, and then clean with HF+HNO3 mixed acid. S5: After cleaning, perform water washing, ultrasonic cleaning and drying. Set up a cleaning material detection system. After drying, test the cleaned cleaning material to see if it is qualified. Unqualified products are returned to the second step for re-cleaning, and qualified products are packaged and put into storage.

[0006] As a preferred technical solution of this application, in step S2, the mixer stirs the cleaning material for 5-10 minutes to remove more than 98% of the silica sludge from the cleaning material.

[0007] As a preferred technical solution of this application, the S4 step involves soaking in HF acid for 1-3 hours.

[0008] As a preferred technical solution of this application, in step S4, the HF+HNO3 mixed acid is used for cleaning, with a cleaning ratio of 1:5-1:15 and a cleaning time of 80s-240s.

[0009] As a preferred technical solution of this application, in step S5, the cleanliness of the cleaning material is tested. If the amount of silica mud is less than 0.5%, it is considered a qualified product; otherwise, it is considered an unqualified product.

[0010] As a preferred technical solution of this application, the cleaning material detection system in step S5 includes a silica mud detection module, a CCD camera detection module, a data collection module, a data transmission module, a central processing module, a display module, an alarm module, and a sorting control module.

[0011] As a preferred technical solution of this application, the silica mud detection module and the CCD camera detection module are connected to the data collection module, the data collection module is connected to the data transmission module, the data transmission module is connected to the central processing module, and the central processing module is connected to the display module, the alarm module, and the sorting control module.

[0012] As a preferred technical solution of this application, the output terminals of the silica mud detection module and the CCD camera detection module are connected to the input terminal of the data collection module. The output terminal of the data collection module is connected to the input terminal of the central processing module through the data transmission module. The output terminal of the central processing module is connected to the input terminals of the display module, the alarm module, and the sorting control module.

[0013] Beneficial Effects: Compared with existing technologies, this invention provides a single-crystal cleaning process for cleaning materials, which has the following beneficial effects: This single-crystal cleaning process uses a mixer to clean the cleaning materials, quickly removing more than 98% of the silica sludge from the surface of the cleaning materials, saving labor costs and time, and improving cleaning cleanliness; it uses high-purity composite alkali for washing, reducing alkali costs while effectively removing oil and impurities from the surface of the cleaning materials; it can quickly clean contaminated cleaning materials, achieving the purpose of recycling the cleaning materials; this design, through the design of the cleaning process, achieves both rapid cleaning of the cleaning materials and ensures the quality of the cleaning materials. This design is applicable to... This method is suitable for cleaning contaminated machine materials. It achieves the same cleanliness level as the cleaned single-crystal recycled material, reducing raw material costs after reuse in crystal pulling. Before acid washing, a mixer is used to stir and clean the machine materials, which can quickly remove the silicon sludge on the machine materials. After cleaning, alkaline washing is used to ensure that there are no oil stains, silicon sludge, or other substances on the cleaned machine materials before normal acid washing. It is suitable for machine material cleaning processes, improves the cleanliness of machine materials, and increases the quality of products produced after reuse by 10% and the output by 5%. The entire single-crystal machine material cleaning process has a simple structure, is easy to operate, and has better results than traditional methods. Detailed Implementation

[0014] A single-crystal cleaning process for cleaning materials specifically includes the following steps: S1: Silicon material removed from the machine tool after machining and collected in a centralized manner is called machine cleaning material; S2: The cleaning material is shipped to the silicon material workshop. After receiving the cleaning material, the silicon material workshop first places the cleaning material into a mixer, similar to a cement mixer. The mixer container is made of non-metallic material, and the cleaning material is stirred and cleaned. S3: After stirring, take out the raw material, sort and magnetically separate it, and then wash it with alkali. Use high-purity compound alkali to remove oil and other substances from the cleaning material. S4: Perform ultrasonic water washing until the pH value of the water reaches neutral, then soak in HF acid for a certain period of time, then perform water washing and ultrasonic washing again, and then clean with HF+HNO3 mixed acid. S5: After cleaning, perform water washing, ultrasonic cleaning and drying. Set up a cleaning material detection system. After drying, test the cleaned cleaning material to see if it is qualified. Unqualified products are returned to the second step for re-cleaning, and qualified products are packaged and put into storage.

[0015] Furthermore, in step S2, the mixer agitates the cleaning material for 5-10 minutes to remove more than 98% of the silica sludge from the cleaning material.

[0016] Furthermore, in step S4, the sample is soaked in HF acid for 1-3 hours.

[0017] Furthermore, in step S4, a mixed acid of HF and HNO3 is used for cleaning, with a cleaning ratio of 1:5 to 1:15 and a cleaning time of 80s to 240s.

[0018] Furthermore, in step S5, the cleanliness of the cleaning material is tested. If the amount of silica sludge is less than 0.5%, it is considered a qualified product; otherwise, it is considered an unqualified product.

[0019] Furthermore, the cleaning material detection system in step S5 includes a silica mud detection module, a CCD camera detection module, a data collection module, a data transmission module, a central processing module, a display module, an alarm module, and a sorting control module.

[0020] Furthermore, the silica mud detection module and the CCD camera detection module are connected to the data collection module, the data collection module is connected to the data transmission module, the data transmission module is connected to the central processing module, and the central processing module is connected to the display module, the alarm module, and the sorting control module.

[0021] Furthermore, the outputs of the silica mud detection module and the CCD camera detection module are connected to the input of the data collection module. The output of the data collection module is connected to the input of the central processing module through the data transmission module. The output of the central processing module is connected to the input of the display module, the alarm module, and the sorting control module.

[0022] Example 1: After the machined material is collected, it is shipped to the silicon material workshop. Upon receiving the cleaned material, the workshop first places it into a mixer (similar to a cement mixer, but the mixer container is made of non-metallic material) and mixes it for 5 minutes to remove a certain amount of silica sludge. After mixing, the raw material is removed and sorted and magnetically separated. After sorting, it is washed with alkali using high-purity compound alkali to remove oil and other substances from the cleaned material. Then, it is ultrasonically washed with water until the pH value of the water reaches neutral. Then, it is soaked in HF acid for 1 hour, followed by water washing and ultrasonication. Then, it is cleaned with a mixture of HF and HNO3 acid at a ratio of 1:5 for 80 seconds. After cleaning, it is washed with water, ultrasonicated, and dried. After drying, it is packaged and stored for testing. At this point, the silica sludge adhesion rate on the surface of the cleaned material is 0.5%.

[0023] Example 2: After the machined material is collected, it is shipped to the silicon material workshop. Upon receiving the cleaned material, the workshop first places it into a mixer (similar to a cement mixer, but the mixer container is made of non-metallic material) and mixes it for 8 minutes to remove a certain amount of silica sludge. After mixing, the raw material is removed and sorted and magnetically separated. After sorting, it is alkaline washed using high-purity compound alkali to remove oil and other substances from the cleaned material. Then, it is ultrasonically washed until the pH value of the water reaches neutral. Then, it is soaked in HF acid for 2 hours, followed by water washing and ultrasonication. Then, it is cleaned with a mixture of HF and HNO3 acid at a ratio of 1:10 for 160 seconds. After cleaning, it is washed, ultrasonicated, and dried. After drying, it is packaged and stored for testing. At this point, the silica sludge adhesion rate on the surface of the cleaned material is 0.35%.

[0024] Example 3: After the machined material is collected, it is shipped to the silicon material workshop. Upon receiving the cleaned material, the workshop first places it into a mixer (similar to a cement mixer, but the mixer container is made of non-metallic material) and mixes it for 10 minutes to remove a certain amount of silica sludge. After mixing, the raw material is removed and sorted and magnetically separated. After sorting, it is washed with alkali using high-purity compound alkali to remove oil and other substances from the cleaned material. Then, it is ultrasonically washed with water until the pH value of the water reaches neutral. Then, it is soaked in HF acid for 3 hours, followed by water washing and ultrasonication. Then, it is cleaned with a mixture of HF and HNO3 acid at a ratio of 1:15 for 240 seconds. After cleaning, it is washed with water, ultrasonicated, and dried. After drying, it is packaged and stored for testing. At this point, the silica sludge adhesion rate on the surface of the cleaned material is 0.15%.

[0025] Stirring time (min) HF acid immersion time (h) HF + HNO3 ratio Cleaning time (s) Silica mud adhesion rate (%) Pass rate (%) Example 1 5 1 1：5 80 0.5 99 Example 2 8 2 1：10 160 0.35 99.3 Example 3 10 3 1：15 240 0.15 99.7 The cleaning process utilizes a mixer to quickly remove over 98% of the silica sludge from the surface of the cleaning material, saving labor costs and time while improving cleanliness. High-purity composite alkali is used for washing, reducing alkali costs while effectively removing oil and impurities from the surface. Before acid washing, the cleaning material is agitated and cleaned using a mixer to quickly remove any silica sludge. After cleaning, alkali washing is performed to ensure the material is free of oil, silica sludge, and other contaminants before normal acid washing. This allows for rapid cleaning of contaminated material, facilitating its reuse. This design achieves rapid cleaning while maintaining the quality of the cleaning material, making it suitable for cleaning contaminated material. The cleanliness of the cleaned material is consistent with that of clean single-crystal recycled material, reducing raw material costs after reuse in crystal pulling. This design improves the cleanliness of the cleaning material, resulting in a 10% increase in product quality and a 5% increase in output after reuse.

[0026] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A single-crystal cleaning process for cleaning materials, characterized in that: Specifically, the following steps are included: S1: Silicon material removed from the machine tool after machining and collected in a centralized manner is called machine cleaning material; S2: The cleaning material is shipped to the silicon material workshop. After receiving the cleaning material, the silicon material workshop first places the cleaning material into a mixer, similar to a cement mixer. The mixer container is made of non-metallic material, and the cleaning material is stirred and cleaned. S3: After stirring, take out the raw material, sort and magnetically separate it, and then wash it with alkali. Use high-purity compound alkali to remove oil and other substances from the cleaning material. S4: Perform ultrasonic water washing until the pH value of the water reaches neutral, then soak in HF acid for a certain period of time, then perform water washing and ultrasonic washing again, and then clean with HF+HNO3 mixed acid. S5: After cleaning, perform water washing, ultrasonic cleaning and drying. Set up a cleaning material detection system. After drying, test the cleaned cleaning material to see if it is qualified. Unqualified products are returned to the second step for re-cleaning, and qualified products are packaged and put into storage.

2. The single-crystal cleaning process according to claim 1, characterized in that: In step S2, the mixer stirs the cleaning material for 5-10 minutes to remove more than 98% of the silica sludge from the cleaning material.

3. The single-crystal cleaning process according to claim 1, characterized in that: In step S4, the sample is soaked in HF acid for 1-3 hours.

4. The single-crystal cleaning process for cleaning materials according to claim 1, characterized in that: In step S4, the HF+HNO3 mixed acid is used for cleaning, with a cleaning ratio of 1:5 to 1:15 and a cleaning time of 80s to 240s.

5. The single-crystal cleaning process for cleaning materials according to claim 1, characterized in that: In step S5, the cleanliness of the cleaning material is tested. If the amount of silica mud is less than 0.5%, it is considered a qualified product; otherwise, it is considered an unqualified product.

6. The single-crystal cleaning process according to claim 1, characterized in that: The cleaning material detection system in step S5 includes a silica mud detection module, a CCD camera detection module, a data collection module, a data transmission module, a central processing module, a display module, an alarm module, and a sorting control module.

7. The single-crystal cleaning process according to claim 6, characterized in that: The silica mud detection module and CCD camera detection module are connected to the data collection module, the data collection module is connected to the data transmission module, the data transmission module is connected to the central processing module, and the central processing module is connected to the display module, the alarm module, and the sorting control module.

8. The single-crystal cleaning process for cleaning materials according to claim 6, characterized in that: The output terminals of the silica mud detection module and the CCD camera detection module are connected to the input terminal of the data collection module. The output terminal of the data collection module is connected to the input terminal of the central processing module through the data transmission module. The output terminal of the central processing module is connected to the input terminals of the display module, the alarm module, and the sorting control module.