Microchip reuse: Environmental rationale and design implications

The last decade has seen unprecedented growth in the variety and number of consumer electronics. Most of these devices, be it computers, game consoles or cell phones, require highly sophisticated semiconductors such as CPUs and memory chips. At the same time, actual lifetimes of almost all electronic devices are decreasing. Computers are replaced after 3 years or less, cell phones on average every 18 months. Microchips are therefore only used for a fraction of their technical lifetimes. Since the environmental impacts of semiconductor manufacturing are very large, it seems obvious that, for environmental reasons alone, microchips should be reused. Reality, however, is more complex, one important reason for this is Moore´s law, which predicts a doubling of transistor density on integrated circuits every 18 months. Moore´s law challenges the conventional wisdom that reuse always reduces environmental impact, since it implies that for a given computational demand, both required die size and use phase energy demand decrease with every new microchip generation. The environmental benefits of displaced microchip production are thus less than might be expected, and reuse also foregoes the use phase energy savings that come with each new microchip generation.