In previous work we proposed a simple constitutive equation that describes the electromigration failure kinetics in naturally passivated Al(Cu) quasi-bamboo lines. The time to failure, tf obeys the relation, tf = t0 exp (−l/t0), where t0 and l0 are characteristic constants and l is the length of the polygranular segment that causes failure (which is ordinarily the longest polygranular segment in the line). The present paper gathers the data supporting this relation, which includes tests on lines as-patterned and annealed at low and high temperature, and examines the dependence of the factors t0 and l0 on current density, test temperature, line geometry, and Al2Cu precipitate distribution. The experimental data suggest that to varies geometrically with j, with exponent n ≈ 2.8, and exponentially with T−1, with activation energy of ∼0.69 eV. It also varies with the line width and the distribution of Al2Cu precipitates. On the other hand, l0 is only weakly dependent on current density and temperature, but may vary with the ratio of line width to grain size (w/G).