The Role of Silica Powder
Silica powder is the most important filler in Epoxy Molding Compounds (EMC), accounting for 70-90% of the composition. Its main functions include:
1. Lowering Coefficient of Thermal Expansion
Silica powder has a much lower CTE than epoxy resin. Adding it significantly reduces the overall CTE of the molding compound, making it more compatible with silicon chips and lead frames, and reducing stress during thermal cycling.
2. Improving Thermal Conductivity
As electronic products become smaller and more powerful, heat dissipation becomes critical. High-filled spherical silica powder can improve the thermal conductivity of the molding compound, helping chip cooling.
3. Reducing Mold Shrinkage
Silica filling reduces shrinkage during epoxy curing, improving package dimensional accuracy and reducing warpage.
Key Selection Criteria
For electronic packaging applications, silica powder selection should consider these key parameters:
- Particle size distribution: Proper particle size gradation for maximum packing density
- Sphericity: Spherical silica has better flowability and higher loading
- Purity: Low sodium, iron, and chloride content for insulation performance
- Alpha radiation: Low-alpha silica reduces soft errors in memory devices
Maylynk offers a full range of electronic-grade silica powder products, including crystalline, fused, and spherical silica, meeting different packaging grade requirements. Contact us for samples and technical datasheets.