FPC circuit board is a flexible circuit board, and silicone oil will be transferred when pressing the release film. The flexible circuit board is a material with high heat resistance and good dimensional stability. It is pressed together with the covering film with mechanical protection and good electrical insulation performance to form the final product. The surface and inner conductors of double-sided and multilayer printed circuit boards are metallized to realize the electrical connection of the inner and outer circuits. Silicone oil cleaning agent uses a water polyol based mixture synthesized by anionic and non-ionic surfactant to produce a neutral concentrate. Silicone oil cleaning agent is a medium cleaning agent made of imported formula, which has high cleaning capacity, purification and pollution characteristics, can be rinsed and biodegradable. No skin damage and corrosivity. Cleaning method 1: ultrasonic cleaning 1. Dilution ratio: detergent: water=1:5-20, 2. Cleaning process: detergent: water=1:5-20 diluted (ultrasonic cleaning at 45-75 ℃ for 3-5 minutes) → rinse with clean water → dry in the air. (For those with high degree of pollution, increase the temperature and extend the cleaning time) Cleaning method II: spray cleaning 1. Dilution ratio: detergent: water=1:5-20, 2. Cleaning process: detergent: water=1:5-20 diluted (spray cleaning at 60-80 ℃) Time: 5-10 minutes (depending on the degree of pollution, extend the cleaning time) → rinse with clean water until clean → dry in the air. Cleaning method 3: Immersion cleaning 1. Dilution ratio: Detergent: water=1:5-20, 2. Cleaning process: Detergent: water=1:5-20 Dilute → Immerse the cleaning substance (continuously stir or brush), the cleaning time is 15-30 minutes, the temperature is above 60-80 ℃ (the cleaning time can be extended depending on the degree of contamination) → Rinse with clean water until clean → Dry in the air.