Development of lead (Pb)-free interconnection materials for microelectronics

Although the amount of Pb or Pb-containing solders used in microelectronics counts only a small fraction of the total Pb usage, the demand for manufacturing "green" products has promoted active research and development for the Pb-free interconnection materials in the recent years. As a result, several candidate materials are now available in two categories: Pb-free solders and electrically conducting adhesives. In this paper, the new development activities of both materials are briefly reviewed in terms of their promising properties, applications, and concerns.