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96 DESIGN007 MAGAZINE I JUNE 2020 approach to manufacturing electronics with- out solder. Visit I-007eBooks.com to download this and other free, educational titles. References 1. G.C. Munie, L. Turbini, D. Berneir, J. Gamalski, & D.W. Bergman, "Examining the Environmental Impact of Lead- Free Soldering Alternatives," Proceedings of IEEE Inter- national Symposium on Electronics and the Environment, San Francisco, California, May 2000. 2. H. Miller, "Lead-free Electronic Solder, Why?" Infra- FOCUS, 2002. 3. nepp.nasa.gov/WHISKER 4. L. Turbini, "The Real Environmental Cost of Lead- Free Soldering," Solid State Times, Volume 4, Issue 3, July 2002. 5. "Solders in Electronics: A Life-Cycle Assessment," U.S. Environmental Protection Agency August 2005. 6. K. Hodal, "Death Metal: Tin Mining in Indonesia," The Guardian, November 23, 2012. Joe Fjelstad is founder and CEO of Verdant Electronics and an interna- tional authority and innovator in the field of electronic interconnection and packaging technologies with more than 185 patents issued or pending. To read past columns or contact Fjelstad, click here. In the 40 years since the company's founding, Kyoto Semiconductor Co., Ltd., Tsuneo Takahashi, president and CEO, and headquartered in Fushimi Ward, Kyoto, has led the industry with optical solutions built from world-stan- dard technologies and with Japanese quality and atten- tion to production detail. They have announced the development of a two- wavelength Photodiode, the KP-2 Two-tone photodiode KPMC29, in the industry's smallest class and capable of being surface-mounted, with silicon and indium-gallium- arsenide photodiodes, with photosensitivity for a wide range of wavelengths, from 400 to 1,700 nm, arrayed along the same light axis. Development Background Spectroscopic analysis technology, that allows for the identification of objects and their characteristics with- out needing direct contact with those objects, by reflecting light of those objects and measuring the degrees of transmission and reflection, is increasingly needed in a wide range of fields, includ- ing medicine, production, and se- curity. Spectroscopic analysis re- lies on two factors for successful use in identifying a wide range of objects: a wider range of wavelengths, or colors, for the source wavelengths, and a wider range of sensitivity for those wavelengths with the photodiode end. Development was therefore undertaken to meet these product needs. Product Characteristics 1. A wider range of wavelength sensitivity (400~1,700nm). To expand the wavelength range, we layered both silicon photodiodes, which are sensitive to shorter wavelengths, and indium-gallium-arsenide photodiodes, which are sen- sitive to longer wavelengths, along the same light axis. 2. A compact surface-mountable package in the in- dustry's smallest class. To successfully make this KP-2 two-tone PD smaller, the indium-gallium-arsenide photo- diodes were laid down in pits arranged on the base for the silicon photodiodes, which ordinarily allows light to pass through. This allowed for the pack- age height to be as low as pos- sible. (Patents have been filed.) Compared to earlier products from Kyoto Semiconductor, the volume ratio has been reduced to 1/8. (Source: Business Wire) Kyoto Semiconductor Develops Broad Range Sensitivity Photodiode in Industry's Smallest Class