Application of low hydrogen silicone oil in electronic potting glue
Low hydrogen silicone oil (usually 0.1%~0.5% hydrogen content) is a functional silicone material. It has low active hydrogen content in its molecular structure, mild reaction, controllable crosslinking density and other characteristics, and is widely used in the field of electronic potting glue. It has excellent performance in improving the weather resistance, electrical insulation and mechanical properties of potting glue, and is especially suitable for the protection of electronic components with high reliability requirements.
1. As a cross-linking agent to improve curing performance
Low hydrogen silicone oil can form a three-dimensional network structure with vinyl silicone oil under the action of platinum catalyst through silylation reaction to achieve curing of potting glue. Its low hydrogen content makes the reaction speed moderate, avoiding internal stress or bubble problems caused by intense heat release, and is particularly suitable for precision circuit potting. For example, in LED driver power modules, low hydrogen silicone oil-based potting glue can be cured evenly, reduce shrinkage (<0.5%), and protect internal solder joints from thermal expansion and contraction stress damage.
2. Optimize high temperature resistance and electrical performance
Electronic devices may generate high temperatures when working (such as automotive electronics reaching more than 150°C). The Si-O-Si main chain structure formed by low-hydrogen silicone oil is stable, giving the potting compound excellent high temperature resistance (-50°C~200°C) and dielectric strength (>15 kV/mm). In the battery management system (BMS) of new energy vehicles, this type of potting compound can withstand high temperature and high humidity environments for a long time, and the insulation resistance retention rate exceeds 90%.
3. Enhance environmental adaptability
By adjusting the amount of low hydrogen silicone oil added (usually 5%~20%), the flexibility and hardness of the potting compound can be balanced (Shore A 30~80). For example, the potting compound for photovoltaic inverters needs to resist UV aging. After adding low hydrogen silicone oil, the yellowing index ΔYI<2 in the QUV accelerated aging test, which is better than traditional epoxy resin.
4. Solve the contradiction between bonding and air permeability
The molecular chain segments of low-hydrogen silicone oil have good fluidity and can penetrate into the microscopic gaps of components to improve the interfacial adhesion (peel strength>1.5 N/mm). At the same time, the microporous structure formed after curing allows water vapor to diffuse (moisture permeability <10 g/m²·day), avoiding condensation damage to the circuit in a closed environment, and is suitable for outdoor 5G base station RF module packaging.
5. Typical cases
IGBT module packaging: The use of low-hydrogen silicone oil potting glue can reduce thermal resistance by 20% and extend the life of power devices.
Consumer electronics waterproof glue: such as smart watch charging contact sealing, passing IP68 test and maintaining a smooth touch.
Conclusion
Low hydrogen silicone oil achieves precise control of potting performance through molecular design. With the development of industries such as 5G and electric vehicles in the future, its application in functional potting adhesives such as high thermal conductivity and flame retardancy will be further expanded.
