Low-resistance copper conductive balls that prevented migration

The demand for flexible displays (e.g. foldable and rollable displays) has recently increased, thus necessitating the development of various component technologies. An anisotropic conductive film, which is a conventional surface mount technology, is deemed more necessary than soldering for the implementation of a flexible display. However, it is still difficult to secure the electrical conductivity and reliability of the conductive ball used in the anisotropic conductive film. In this paper, a copper conductive ball having a lower resistance than the conventional conductive ball was fabricated. It has a lower contact resistance than nickel and gold, and the reliability issue, which is a disadvantage of copper, is secured by blocking the reaction with oxygen and coating a thin corrosive solution.