Mineral Filler

Mineral filler is an inorganic particulate material incorporated into electrical grade epoxy resin compounds to modify their physical, thermal, and electrical characteristics. These fillers, typically composed of silica, alumina, calcium carbonate, or other mineral oxides, are precisely engineered in particle size distribution and surface treatment to improve dielectric strength, thermal conductivity, arc resistance, dimensional stability, and mechanical strength while maintaining processability for encapsulation, potting, and insulation of electrical components.

Mineral fillers function by dispersing within the epoxy resin matrix, creating a composite material where the inorganic particles interact with the polymer chains. This interaction enhances properties through mechanisms such as: increasing thermal conductivity by providing pathways for heat transfer, improving dielectric properties by reducing moisture absorption and polarization losses, enhancing mechanical strength via particle reinforcement, reducing coefficient of thermal expansion (CTE) to match other materials, and increasing flame retardancy through endothermic reactions or char formation.