Environmentally friendly composite coating steels for board level shielding application

The demands of environmentally friendly and whisker-generation-resistant board level shields are increasing with endless marking requirements for high EMC performance and cost-effective electronic products. As a result, some environmentally friendly composite plating steels, such as chromate-free electrogalvernized steel (ZE-38) and ECO-TRIO steel, have been developed and emerged as promising board level shielding materials. This paper assesses and evaluates the acceptability and performance of these materials in accordance with the requirement of board level shielding applications. With good solderability, high resistance to whisker generation, relatively high surface conductivity, and satisfactory corrosion resistance, the ECO-TRIO and ZE-38 steels have great potential to take the place of Tin plated cold rolled steels and Nickel Silver alloys as next generation board level shielding materials.