Assembly technology using lead-free solder

In the process of complying with the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment (RoHS) Directive enforced on July 1, 2006, the major technical issue to be addressed regarding the six substances restricted by RoHS is replacing lead, which is used a variety of ways in said equipment. The replacement of lead, especially with regard to solder (the so-called basic material of electronic assembly), requires controlling the heat resistance of electronic components. Moreover, a means must be devised to maintain uniform temperature for each material and component at reflow soldering since commonly used tin-silver-copper (Sn-Ag-Cu) solder, if adopted, requires a higher soldering temperature than lead containing solder. Additionally, it is important to clarify the properties, quality, and reliability of any new, alternative solder materials. Fujitsu has been engaged in comprehensive engineering, such as developing basic lead-free solder materials, to apply lead-free solder to its products. This paper introduces Fujitsu's activities toward addressing the technical issues posed by lead-free soldering technology.