European Producers Call For Lead-Free World Standard
Brian Dance, Contributing Editor -- Semiconductor International, 9/1/2001
European semiconductor manufacturers have proposed a standard
for defining and evaluating lead-free semiconductor devices. This proposal is
from Europe's three largest manufacturers — Siemens (Munich, Germany), Philips (Eindhoven,
Netherlands) and STMicroelectronics (Geneva, Switzerland). The proposed standard provides a common definition of "lead-free" and assesses factors such as solderability and reliability of the alternative materials.
Lead, with tin, is a critical component of the solder used for printed circuit board assembly. It also is widely used in semiconductor packaging, e.g., coating package leads, die attachment in power IC packages, and as balls of ball grid array packages. In nature, lead is often found with other metals, so removing all traces of lead from metals used in lead-free solders is not economically viable.
The companies say that the lack of any internationally agreed upon standards and methodologies for evaluating the quality and reliability of lead-free technologies has been a major barrier to eliminating the use of lead in the industry. "Many different kinds of lead-free solder alloys and soldering processes are being investigated worldwide using combinations of elements, such as tin, silver, copper, bismuth, indium and zinc," said Carlo Cognetti, vice president for new package development at STMicroelectronics. "All of these require increased temperature profiles relative to the well-known tin lead alloys during the soldering process. To accelerate the transition to lead-free technology, the electronics industry needs a common approach to quantifying solderability, heat resistance and other issues that affect reliability."
"Europe has taken the lead in proposing the world's first legislation to eliminate lead from electronic equipment and components," said Leo Klerks, environmental officer at Philips Semiconductors. "Our three companies' interest in using lead-free soldering technologies has partly been fueled by legislative restrictions from the European Commission. Effective from Jan. 1, 2006, materials such as lead, mercury, cadmium and others will be forbidden in electrical and electronic devices."
The three producers will introduce their lead-free products far in advance of legislative deadlines, making fully qualified lead-free components available from the end of this year. The companies propose an upper limit in lead-free components of 0.1% lead in each individual material, not in the whole package or component. They plan to continue their cooperation on standards and evaluation, but will pursue individual research programs to find the most economically and technologically effective ways to remove lead from electronics products.
