In the field of optoelectronics and semiconductor packaging, fluorosilicone oil, due to its unique chemical and physical properties, is becoming a key material for high-end protective coatings. With the miniaturization of chip manufacturing processes, the popularity of 3D packaging, and the increased environmental sensitivity of optoelectronic devices, packaging materials not only need to provide mechanical protection but also must possess excellent dielectric properties, hydrophobicity, solvent resistance, and long-term stability - fluorosilicone oil precisely meets these stringent requirements.
The fluorosilicone oil molecules' fluorinated alkyl groups give them extremely low surface energy, enabling their coatings to have excellent hydrophobic and oleophobic properties. This effectively prevents moisture, salt fog, and organic pollutants from invading the chip interior, significantly enhancing the reliability of the device in high-humidity and high-pollution environments. Additionally, its main chain is a flexible Si–O structure, with a thermal expansion coefficient close to that of silicon substrates, which can alleviate thermal stress and prevent the packaging layer from cracking. Moreover, fluorosilicone oil shows strong tolerance to chemicals such as acetone, isopropanol, and developing solutions in semiconductor processes, and is not prone to swelling or degradation.
In optoelectronic applications, some modified fluorosilicone oils can also regulate refractive index and be used as the passivation layer or optical coupling coating for LED chips, preventing moisture while reducing light loss. In recent years, low dielectric constant fluorosilicone coatings have also been explored for the dielectric layer in advanced packaging to reduce signal delay and crosstalk.
Although the cost is relatively high, with breakthroughs in domestic technology, fluorosilicone oil is gradually moving from being "optional" to "necessary" in semiconductor and optoelectronic packaging, becoming the invisible guardian that ensures the high reliability of next-generation microelectronic devices.