Lead free interconnect materials for the electronics industry

摘要

Considerable development and research has been conducted over thelast 25 years by many areas of manufacturing to reduce the use of leadand to limit human exposure to lead and products containing lead. Smalllevels of lead can damage the nervous system of children. Major sourcesof lead are ingested paint, 75%, and drinking water, 20%. Theelimination of lead from all manufacturing products, whether throughlegislation or through tax incentives, will have a significant impact onthe electronic interconnect technologies. In 1993 the National Centerfor Manufacturing Sciences (NCMS), a not-for-profit cooperative researchconsortium of more than 215 U.S. North American manufacturers,established multi-year programs. Lead Free Solder Project (LFSP) andConductive Polymer Interconnect Project (CPIP) involving participantsfrom industry, academia, and national laboratories. The objective ofthese programs is to identify lead free solder alternativereplacement(s) and conductive polymeric materials for lead bearingsolders in the electronics industry. The new materials must meet theinterconnect performance requirements at operating environments rangingfrom-55 to +180 degrees centigrade. Numerous lead free alloy solders,each exhibiting unique properties, have been used by electronicmanufacturers in specific applications. The major usage of conductiveadhesives has been in consumer electronics and children's toys. Beforeany of these new lead free materials can be applied to the widelydiverse electronics industry considerable research and development isrequired. The NCMS programs involve a study of the material properties,manufacturability, modeling and reliability predictions, economicimpact, and toxicological properties