Identification of IC chip based on information formed on high-molecular film

摘要

A method is disclosed for easily identifying an IC chip. A high-molecular film is formed on the surface of an IC chip, and the color of the film is changed by irradiating the film with a laser beam of a specified wavelength range. A molecular structure in the high-molecular film is caused to change by a laser beam, which in turn changes the color of the film. This property is used to mark various data and to identify an IC chip with a difference in film color between an irradiation area and a non-irradiation area of the laser beam.