Electrolytic copper foil, negative electrode for lithium ion secondary battery, lithium ion secondary battery, rigid printed wiring board and flexible printed wiring board

摘要

An object of the present invention is to provide an excellent handling property in which the tensile strength is not significantly reduced by a high-temperature heat treatment applied in the manufacturing process of a rigid printed wiring board, a flexible printed wiring board or a lithium ion secondary battery, When a lithium ion secondary battery is configured as a current collector for a negative electrode, an electrolytic copper foil capable of obtaining a good cycle life is provided. The electrolytic copper foil of the present invention contains 150 ppm or more of carbon, 200 ppm or more of chlorine and 50 ppm or less of sulfur as impurities in the foil, and after heating at 450 ° C. for 1 hour at a normal tensile strength of 450 MPa or more. The tensile strength measured at room temperature is 350 MPa or more. [Selection] Figure 1