Several modeling issues in LED, 3D-SiP, and nano interconnects

Multi-physics multi-scale modeling issues in various stages of the LED manufacturing, 3D-SiP, and nano interconnects have been discussed. Molecular dynamics (MD) and finite element method (FEM) have been used to study the scale effect of the material properties and the prediction of the module behaviors which are critical to LED fabrication. We propose a new concept to integrate multi-physics/multi-scale modeling as a simulation platform to assist LED design and fabrication. For 3D-SIP, nonlinear thermal stresses and strains at the interfaces between copper/dielectric layer and dielectric layer/silicon of copper filled and polymer filled through silicon via have been studied by finite element simulation. The effects of different configurations including different diameters of copper via and polymer filled, aspect ratios (the thickness of silicon vs. the diameter of copper via) and different thickness of the dielectric layer on the stresses and strains state were analyzed. For nano interconnects, classic molecular dynamics are used to modeling the process of carbon nanotube bonding onto the metal electrodes, both local heating and wetting process are modeled. It is indicated that the simulation that relies on multi-physics/multi-scale modeling has the potential to significantly reduce development costs and optimize the fabrication processes of LED, SIP and nano interconnects.