Lead-Free Technology in Adachi, Tokyo - June 2004 to 2020s Development

Lead-Free Technology in Adachi, Tokyo - June 2004 to 2020s Development

2004.
Senju Metal Industry Co., Ltd. of Adachi-ku, Tokyo, was an industry leader in the development of lead-free solder in response to increasing environmental regulations. The company's technology used an alloy based on tin, silver, and copper, which was attracting attention as an environmentally friendly alternative to conventional lead solder. However, the melting point of this alloy system was 30°C higher than that of conventional products, leaving an issue for applications requiring heat resistance. Nevertheless, Senju Metal continued to make improvements to overcome this issue, and the product has been highly acclaimed both in Japan and overseas.

The 2010s
In the 2010s, Senju Metal expanded the range of applications for its lead-free technology, accelerating its use in the automotive and consumer electronics sectors. In 2013, the company launched the ECOSOLDER™ brand and introduced products compliant with the European Union's Restriction of Hazardous Substances (RoHS) Directive. This directive severely restricts the use of lead in electrical and electronic products, and Senju Metal's technology has demonstrated its ability to adapt to international regulations.

Furthermore, in 2015, a new production line was introduced in Adachi-ku, Tokyo, increasing production capacity by 25% over the previous year. This brought annual production to 15,000 tons, covering more than 80% of the domestic market. Also in the same year, we applied recycling technology to increase the reuse rate of used solder from 20% to 30%.

The 2020s
In the 2020s, Senju Metal further developed its lead-free solder technology and solidified its position in the global market. The company's annual production of tin-silver-copper alloy-based solders reaches approximately 20,000 tons, 40% of which is exported to the European Union and Asian markets. With the new ECOSOLDER™ series, the melting point has been lowered from 240°C to 215°C, making it suitable for electronic components in automobiles and aircraft that require high heat resistance.

Plans are also underway to increase the reuse rate of used solder from 30% to 45% through the introduction of recyclable alloy technology. 2022 saw a 20% increase in R&D expenditures over the previous year to 6 billion yen, with a focus on new material development and manufacturing process improvements. The contribution to the local economy is also remarkable, and is expected to support approximately 5,000 jobs in 2025, including those in related companies.

Conclusion
Senju Metal Industries' lead-free technology is a model case of one of the sustainable manufacturing industries, as the company has continued its efforts to balance environmental friendliness and economic growth from the technology development stage in 2004 to the product diffusion in the 2010s and market expansion in the 2020s.