In the thermal design of stacked three-dimensional multi-chip module (3D-MCM)

the placement of multiple chips on 3D-MCM substrate has a significant effect on temperature field in the 3D-MCM

thus influences the reliability of the 3D-MCM.The thermal placement optimization of chips in stacked 3D-MCM was studied in this paper

the goal of this work is to decrease temperature and achieve uniform thermal field distribution within stacked 3D-MCM.The average temperature of chips in stacked 3D-MCM was chosen as the evaluation target based on thermal superposition model and equation of heat conduction

and the fitness function for thermal placement optimization was determined.Based on genetic algorithms

chips placement optimization algorithm of thermal model was proposed and the optimization chips placement of stacked 3D-MCM was achieved by corresponding optimization program.Based on this work

the chips placement rules which can be used for directing thermal design of stacked 3D-MCM were summarized.To demonstrate the effectiveness of the obtained optimization chips placement

by using ANSYS

finite element analysis (FEA) was carried out to assess the thermal field distribution of the optimization chips placement in stacked 3D-MCM

the result shows that the thermal field distributions of the optimization chips placement are in good accord with the FEA results.It turns out that the chip placement optimization approach proposed in this work can be effective and robust in providing thermal optimal design of chip placement in stacked 3D-MCM.