Thermal Ratcheting of Solder-Bonded Layered Plates
The cyclic growth and recovery of warpage were observed in experiments on Si/solder/Cu layered plates subjected to cyclic thermal loading . In the present study, the experiments were analyzed using representative material models for the solder and Cu layers in finite element analysis. The warpage growth/recovery behavior observed was reproduced well in the analysis using the Armstrong-Frederick and Ohno-Wang models for the solder and Cu layers, respectively. Material ratcheting due to non-proportional cyclic loading was found to happen in the solder layer as a consequence of the CTE mismatch, while material ratcheting due to proportional cyclic loading occurred in the Cu layer as a result of the significant temperature dependence of viscoplasticity in the solder layer.
Yeong-Maw Hwang and Cho-Pei Jiang
N. Ohno et al., "Thermal Ratcheting of Solder-Bonded Layered Plates", Key Engineering Materials, Vol. 626, pp. 178-181, 2015