LANZHOU, Aug. 6 (Xinhua) -- At the pristine dust-free workshop of Gansu Defu New Materials Co., Ltd., a delicate copper foil, as fine as the wings of a cicada, glides gracefully off the production line.
The company, located in Lanzhou New Area, northwest China's Gansu Province, has the capability to manufacture premium copper foil at an astonishing 4.5-micron thickness, a mere sliver of the width of a human hair
