Toxicity of Lead
1.EPA: Lead and Pb compounds have been cited as one of the top 17 chemicals posing the greatest threat to human life and the environment;
2.Lead from industry wastes will enter the ground water stream, and then the animal or human food chain;
3.Accumulated Lead in human body will lead to nervous and reproductive system disorder, delays in neurological and physical development, reduced production of haemoglobin resulting in anemia and hypertension;
4.OSHA standard: For adult, Pb level in blood should be no more than 50mg/dl, for child, below 30mg/dl.
Definition of "Lead-Free"
1.Up to now, no available international standard;
2.Reference: "Lead-free" for plumbing solders and fluxes, Pb content should be less than 0.2wt% (USA) or 0.1wt% (EU);
3.SO Draft: Pb content in Lead-free solders for electronic assembly should be less than 0.1wt%.
Milestones for Lead-free solders
1991 and 1993: US Senate proposed "Reid Bill" to limit Pb content in solders to less than 0.1%, which was objected by the US manufacturing industry and finally faded out;
From 1991, Several organizations, e.g., NCMS, NIST, DIT, NPL, PCIF, ITRI and JIEP have carried out many investigations on lead-free solders, which totally cost more than 20M dollars and still on the way;
1998: Japanese Home Electronics Recycling Law was revised, push the industry to eliminate Pb in electronics;
Oct. 1998: First mass manufacturing Lead-free electronic product all over the world, Panasonic MiniDisc MJ30;
Jan. 2000: NEMI recommended "standardized" Lead-free solders to the industry, Sn-3.9Ag-0.6Cu for reflow soldering, Sn-3.5Ag or Sn-0.7Cu for wave soldering;
June, 2000: IPC Lead-free Roadmap Draft IV, suggested the North American companies to produce Lead-free products by 2001, with an eye toward total lead elimination by 2004;
Aug. 2000: JEITA Lead-free Roadmap V1.3, suggested Japanese companies to standardize Lead-free electronic assembly by 2003;
Jan. 2002: EU Lead-free Roadmap V1.0, survey upon questionnaire provided important statistic data;
Feb. 13, 2003 : EU proclaimed DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on waste electrical and electronic equipment and on the restriction of the use of certain hazardous substances in electrical and electronic equipment, which means the electronic products in Europe markets must be lead-free since July 1, 2006;
Mar. 2003: Proposal for a directive on the prevention and cure for pollution by the production of electronic products was proposed by Minster of Information Industry, China, which also proposed a deadline of July 1, 2006.