Silica micropowder, as an important non-metallic mineral material, is widely used in various fields such as copper-clad laminates (CCL), epoxy molding compounds (EMC), electrical insulating materials, rubber, plastics, and coatings due to its unique physical and chemical properties.
Copper-Clad Laminates (CCL)
As the core component of printed circuit boards (PCBs), CCLs require properties like high glass transition temperature (Tg), high modulus, low coefficient of thermal expansion (CTE), low dielectric constant (Dk), and low dissipation factor (Df) to enhance the reliability of electronic circuit interconnection and installation. Fillers are the key driver for achieving these performance metrics in CCLs. Common inorganic fillers include silica micropowder, talc, aluminum hydroxide, and magnesium hydroxide. Among them, silica micropowder stands out due to its high thermal stability, low CTE, and low Dk.
The CCL industry’s requirements for silica micropowder mainly focus on particle size, morphology, and surface treatment. Particle size needs to balance dispersibility and processability; theoretically, smaller particles offer better filling effects, but excessively small sizes can lead to agglomeration, poor dispersion, and increased difficulty in mixing and resin coating processes. In terms of morphology, spherical silica micropowder is preferred for its higher packing density, lower CTE, and better wear resistance. Surface treatment not only improves dispersion but also enhances the compatibility between the silica micropowder and the resin system.
Currently, challenges remain for high-purity silica micropowder used in CCLs, including reliance on imports for high-end products, the relatively high cost of certain grades, and the need for further optimization of production processes. Future development directions will focus on high-end product localization, import substitution, and meeting the specific demands of high-frequency and high-speed CCLs.
Epoxy Molding Compounds (EMC)
As a critical semiconductor packaging material, EMC’s requirements for fillers primarily center on reducing the CTE, increasing thermal conductivity, and lowering the Dk. Due to its excellent physical and chemical properties, silica micropowder is a key filler in EMCs, typically constituting 60% to 90% of the compound by weight.
The use of silica micropowder as a filler in EMCs offers significant advantages. Its high purity and low radioactivity effectively reduce the cured compound’s CTE and shrinkage during curing, while simultaneously improving mechanical strength and insulation properties. Furthermore, compared to angular silica powder, spherical silica micropowder offers higher packing density. When the particle size distribution is between 0.1~30μm, the packing density can exceed 92%, potentially reducing epoxy resin usage by up to 50%. The spherical structure also provides excellent flowability, which not only reduces defects like mold flash and air voids but also extends mold life.
Currently, the application of silica micropowder in EMCs also faces challenges. The production technology for high-end products involves high barriers, particularly the complex process for spherical silica, leading to higher costs. In the future, as electronic packaging trends towards higher performance and miniaturization, requirements for particle size distribution, purity, and sphericity of silica micropowder will become even more stringent.
Rubber
Silica micropowder serves as a functional filler in the rubber industry, offering significant application advantages and broad development prospects. The primary demands for fillers in rubber products focus on improving physical mechanical properties, wear resistance, heat resistance, and anti-aging performance. Due to its small particle size, large specific surface area, good heat resistance, and wear resistance, silica micropowder can significantly enhance the tensile strength, modulus, and tear strength of rubber composites. Additionally, its high purity and good dispersibility allow it to form a uniform filler layer within the rubber matrix, further enhancing abrasion resistance and aging resistance.
However, because the surface of silica micropowder contains a large number of acidic silanol groups, compatibility with the rubber matrix can be poor, potentially affecting the overall performance of the composite. Currently, researchers primarily address this issue through surface modification techniques, commonly using silane coupling agents and titanate coupling agents. These modifiers can react with the hydroxyl groups on the silica surface, reducing its surface energy and thereby improving compatibility and dispersion within the rubber matrix.
Looking ahead, with increasing demand for high-performance rubber materials, the development of high-purity, ultra-fine silica micropowder and new specialized modifiers will be important trends. Concurrently, in-depth research into modification mechanisms and how to better leverage the synergistic effects of modifiers will be major focuses in the field of silica surface modification.
Other Applications
As a high-performance inorganic non-metallic material, silica micropowder is also widely used in coatings, electrical insulating materials, and adhesives. In the coatings industry, it significantly enhances corrosion resistance, abrasion resistance, insulation properties, and high-temperature resistance. Adjusting the particle size distribution can optimize film density, and it can partially replace titanium dioxide while maintaining hiding power and enhancing heat resistance. In electrical insulating materials, due to its high insulation resistance and high-temperature resistance, silica micropowder is extensively used in insulators and cable accessories for power equipment, effectively preventing current leakage and ensuring safe operation. Furthermore, its application in adhesives and sealants is growing. By enhancing bond strength with resins and reducing the peak exothermic temperature during curing, silica micropowder effectively improves the mechanical properties and aging resistance of adhesives.
Poudre épique
À Poudre épique, we specialize in the advanced production of high-purity and spherical silica micropowder essential for these demanding applications. Our state-of-the-art manufacturing process leverages cutting-edge fluidized bed jet mills integrated with high-precision air classifiers. This sophisticated system is crucial for achieving the superior product qualities required by the industry.
Precision Particle Size Control: Our jet mills provide the intense mechanical energy for efficient comminution, while our classifiers ensure an exceptionally narrow and tightly controlled particle size distribution (PSD). This is vital for optimizing properties like flowability in EMCs, dispersion in coatings, and reinforcement in rubber.
High Purity and Contamination-Free Processing: The grinding mechanism of our jet mills, which relies on particle-on-particle impact within a high-pressure air stream, minimizes contamination from wear parts. This is paramount for producing the high-purity silica micropowder needed for electronic applications like CCLs and EMCs.
Tailored Solutions: We understand that different applications have unique requirements. Our technical expertise allows us to tailor the milling and classification parameters to produce silica micropowders with specific PSDs, morphologies, and surface characteristics, supporting our customers in their material innovation journeys.
By mastering the synergy between fraisage au jet and air classification, Poudre épique delivers consistent, high-performance silica micropowder that meets the rigorous standards of modern industries, empowering our clients to develop next-generation materials.