Elimination of lead in first level semiconductor packaging

Interconnection technology of first and second level of electronic packagin g is based on tin-lead alloys, which provide cheap and reliable solder join ts. International regulations for enviromental protection are addressing th e elimination of lead, and this poses a number of technical challenges. For first level packaging, six different technologies are involved. For fou r of them, Pb-free version is available or close to be qualified; in two ca ses, however, solutions are not ready and will require a long development a ctivity.