Surface conductive shielding material and filled composite shielding material

With the rapid development of modern electronics and information industries, the number of electronic devices that generate electromagnetic wave interference has sharply increased. Electromagnetic wave pollution has become one of the social hazards that countries around the world are concerned about. useConductive metal powder electroplatingDeveloping electromagnetic shielding rubber filling materials is an important technical means to address this pollution.
Conductive shielding technology
　　electromagnetic shielding materialIt is divided into surface conductive shielding materials and filled composite shielding materials. Filled composite shielding materials are a new type of material that has been introduced to the market after surface conductive shielding materials, with great potential to catch up and be extensively developed. As the core technology of filling composite shielding materials, research on conductive fillers is also constantly deepening.
At present, foreign countries have developed various electromagnetic shielding rubber products with different material combinations using this technology.
At present, pure silver powder is mainly used as a conductive filler in China. Silver has excellent conductivity and oxidation resistance, and using silver powder or silver plated fillers as electromagnetic shielding materials has significant shielding effects. However, silver is expensive, has a high density, and lacks market competitiveness. It is only suitable as a shielding material for special occasions and has poor electromagnetic shielding effect on low frequencies, making it difficult to meet the needs of broadband electromagnetic shielding. Copper has good conductivity and a moderate price, but its high density makes it difficult to disperse in the polymer matrix, which affects the electromagnetic shielding effect of composite materials. Moreover, copper powder is prone to oxidation and deterioration, which reduces its conductivity. Nickel powder is not as easily oxidized as copper powder, but its conductivity is lower. In order to improve the comprehensive performance of fillers, copper silver plating or nickel silver plating is often used. Graphite and carbon black have the characteristics of low cost and good dispersion, but they often only have a certain electromagnetic shielding effect at a high content, which can significantly reduce the mechanical properties of the product. Moreover, the product itself is black, affecting the color diversity of the product and limiting its application range. It is also often used in the form of carbon powder nickel plating.
Usually, there are two methods for surface coating of metal powder: electroplating and chemical plating,Advanced Institute (Shenzhen) Technology Co., LtdThrough relevant research and analysis, it has been concluded that electroplating is more stable, efficient, and less polluting than chemical plating, and corresponding research and development have been carried out.