Copper alloy foils for flexible circuits

摘要

A flexible circuit (10) to interconnect two components of an electrical device is formed with a flexible polymeric substrate (14). A copper alloy strip (12) is laminated to the flexible substrate (14). This copper alloy strip (12) is processed to have relatively high strength and an ultimate tensile strength in excess of about 551.6 MPa by alloying additions, by processing, or by a combination of the two. When such a copper alloy strip (12) is laminated to the flexible polymeric substrate (14), the resultant flexible circuit (10) has improved (more cycles to failure) dynamic fatigue performance when compared to both pure copper and dilute copper alloy strips.