The Implications of Adaptability

This invention relates to an improved high performance flexible laminate, comprising: a layer of electrodeposited copper foil overlying a layer of a flexible polymeric material, said copper foil being characterized by an ultimate tensile strength at 23 DEG C. of at least about 60,000 psi, a loss of ultimate tensile strength at 23 DEG C. of no more than about 15% after being annealed at 180 DEG C. for 30 minutes, an average grain size of up to about 1 micron, and a fatigue performance characterized by at least about 5000 cycles to failure when the strain amplitude is about 0.05% to about 0.2%. In one embodiment, the copper foil is electrodeposited using an electrolyte solution characterized by a free chloride ion concentration of up to about 4 ppm and an organic additive concentration of at least about 0.3 ppm.