| abstract |
A basic metallurgical solution is provided for solder-metal interconnect and thermomechanical stress reliability. An integrated circuit chip has a plurality of conductor pads connected to external components by reflow attachment. The chip has a NiTi alloy deposition layer 505 on each pad, and the alloy has a composition and crystal structure that functions in a reversible phase transition under thermomechanical stress, whereby mechanical strain is reduced by the alloy layer. Absorbed. Preferably, the alloy has 55.0 to 56.0 wt% Ni and 44.0 to 45.0 wt% Ti, a thickness of 0.3 to 6.0 µm, and a temperature after deposition. Recrystallize at 450-600 ° C for 4-6 minutes. The brazeable metal layer 506 acts as a diffusion barrier on the alloy after reflow attachment. [Selection diagram] FIG. |