High-value application of silicon micro powder

Silicon micropowder is a non-toxic, odorless, pollution-free inorganic non-metallic material, made from natural quartz (SiO2) or fused quartz (amorphous SiO2 after natural quartz is melted at high temperature and cooled) through multiple processes such as crushing, ball milling (or vibration, air flow milling), flotation, acid washing and purification, and high-purity water treatment.

1 Application in copper-clad laminates

Silicon micropowder is a functional filler. When added to copper-clad laminates, it can improve the insulation, thermal conductivity, thermal stability, acid and alkali resistance (except HF), wear resistance, flame retardancy, bending strength and dimensional stability of the laminates, reduce the thermal expansion rate of the laminates, and improve the dielectric constant of the copper-clad laminates. At the same time, due to the abundant raw materials and low prices of silicon micropowder, it can reduce the cost of copper-clad laminates, so its application in the copper-clad laminate industry is becoming more and more extensive.

Ultrafine crystalline silicon powder

The average particle size of ultrafine silicon powder currently used in copper-clad laminates is 1-10 microns. As the substrates of electronic products develop towards ultra-thinness, fillers are required to have smaller particle sizes. In the future, copper-clad laminates will use ultrafine fillers with an average particle size of about 0.5-1 microns.

Fused silicon powder

Fused silicon powder is a powder made of natural quartz, which is melted at high temperature and cooled with amorphous silicon dioxide as the main raw material, and then processed by a unique process. Its molecular structure arrangement changes from ordered arrangement to disordered arrangement. Due to its high purity, it presents stable chemical properties such as extremely low linear expansion coefficient, good electromagnetic radiation, and chemical corrosion resistance, and is often used in the production of high-frequency copper-clad laminates.

Composite silicon micropowder

Composite silicon micropowder is a glass-phase silicon dioxide powder material made from natural quartz and other inorganic non-metallic minerals (such as calcium oxide, boron oxide, magnesium oxide, etc.) through compounding, melting, cooling, crushing, grinding, grading and other processes. The Mohs hardness of composite silicon micropowder is about 5, which is significantly lower than that of pure silicon micropowder.

Spherical silicon micropowder

Spherical silicon micropowder is a spherical silicon micropowder material with uniform particles, no sharp corners, small specific surface area, good fluidity, low stress and small bulk density, which is made of selected irregular angular silicon micropowder as raw material and processed by high temperature near melting and near spherical method.

Active silicon micropowder

Using active treated silicon micropowder as filler can significantly improve the compatibility of silicon micropowder and resin system, and further improve the moisture and heat resistance and reliability of copper clad board. At present, the domestic active silicon micropowder products are not ideal because they are only simply mixed with silicon coupling agents. The powder is easy to agglomerate when mixed with resin. Many foreign patents have proposed active treatment of silicon micropowder.

2 Application in high-end epoxy resin potting materials

Epoxy resin potting materials are widely used in the potting process of electronic device manufacturing. Potting is an operation process that uses potting materials to reasonably arrange, assemble, bond, connect, seal and protect the various parts of the electrical device according to the specified requirements. Its function is to strengthen the integrity of electronic devices, improve their resistance to external impact and vibration, improve the insulation between internal components and circuits of electronic devices, avoid direct exposure of internal components and circuits of electronic devices, and improve the waterproof, dustproof and moisture-proof performance of electronic devices.

3 Application in epoxy molding compound

Epoxy molding compound (EMC), also known as epoxy resin molding compound or epoxy molding compound, is a powder molding compound made of epoxy resin as the base resin, high-performance phenolic resin as the curing agent, silicon micropowder and other fillers, and a variety of additives. 97% of the global integrated circuit (IC) packaging materials use epoxy molding compound (EMC). The molding process is to extrude EMC into a special mold cavity by transfer molding, embed the semiconductor chip in it, and complete cross-linking and curing molding to form a semiconductor device with a certain structural appearance. In the composition of EMC, silicon micropowder is the most used filler, accounting for 70% to 90% of the weight of epoxy molding compound.