How to ensure the cleanliness and anti-static performance of clean dust-free clothing
Fine dust and static electricity have become an important reason for affecting the quality of electronic products. In order to strengthen the control of fine dust and static electricity in the clean room, it is necessary to pay attention to the cleanliness and electrostatic properties of work clothing.
1. The material requirements for clean and dust-free clothing (including hats and masks) are:
(1) The amount of dust is small, and it is not easy to peel off or break the wire; (2) It is not easy to generate static electricity and it is not easy to adhere particles; (3) It is resistant to organic solvents, cleaning, and steam sterilization; (4) It is not moldy. The clean and dust-free clothing must cover all hair, beard and feet in style, and can prevent the body from falling off to the maximum extent.
2. Standard process for cleaning clean and dust-free clothing:
(1) Sorting: After receiving the clean and dust-free clothing from the customer, it is sorted first, and then stored in a plastic box with a lid to prevent increased pollution.
(2) Pre-treatment: for some damages and buckles that occur during the use of dust-free clothing. Pre-decontaminate the special dirt-type clean clothes to be cleaned.
(3) Dust-free cleaning: The pre-treated dust-free clothing is cleaned by a special channel structure washing machine in the non-control area and then enters the control area (clean room). In the final rinse, the antistatic agent can be used to improve the antistatic properties, but the antistatic agent should be well combined with the fiber and no dust fall off. In order to remove water-soluble contaminants, after washing with clean water, a final wash with distilled solvent is performed to remove oily contaminants. The water used for wet and dry cleaning should be filtered, and the solvent should be distilled. Use a filter membrane with a pore size of less than 0.2 μm at the point of use, and perform more than one filtration as needed.
(4) Dust-free drying: The cleaned anti-static dust-free clothes should be dried in a clean air circulation system dedicated to washing (the drying hot air used is filtered by HEPA).
(5) Folding inspection: after drying, it is folded in a clean room dedicated for washing, and put into a clean polyester bag or nylon bag. It can be double-packed or vacuum-sealed according to requirements. The packaging material is preferably antistatic Good material. Since the folding process is most susceptible to dust, the folding process must be carried out in a high-level clean room. For example, the folding and packaging of 100-level dust-free clothing should be carried out in a 10-level environment.
(6) Cleanliness test: The drum (Helmke Drum) tester can test the number of cleanliness-level dust particles on the cleaned anti-static dust-free clothing.
(7) ESD test: ESD performance check to ensure the anti-static performance of dust-free clothing.
(8) Purification and packaging: anti-static and dust-free clothing that has passed all inspections and is sealed and packaged in a vacuum packaging bag becomes a qualified product.
The dust and static electricity in the clean room are extremely harmful to the product. The clean dust-free clothing can minimize the dust pollution of the human body and prevent the generation of static electricity. Therefore, the dust-free clothing in the clean room must undergo strict testing to ensure its cleanliness and anti-static performance.