关键词: 高保真有限元建模方法, 湿扩散, 均匀化方法

Abstract: Facing the requirements of high environmental adaptability and high integration of in the field of integrated circuits, it is particularly important to study the moisture reliability and multi-scale problems of packing devices. The high-density metal traces and graphic design of electronic packaging structures are the main factors which affect the moisture diffusion. Taking the typical packaging structure of integrated circuits as the research object, the high-fidelity finite element modeling method based on the packaging structure layouts was applied to accurately simulate the influence of the distribution of moisture-insulating materials (such as metal tracing) on the diffusion path of moisture inside the packaging. In view of the mathematical similarity between the Fick’s diffusion equation and the heat conduction equation, the heat transform module in the finite element software was used to simulate the moisture diffusion between organic packaging materials and metal materials. The moisture stress is analyzed considering the arrangement of metal component arrangements based on the moisture-heat analogy method. The high-fidelity finite element modeling method faced the balance between modeling efficiency and resolution of packaging structural layouts. It was verified that by controlling the resolution in the range of 100×100 to 200×200, the modeling time was reduced to 6.044% of the 425×425 high-solution model, while still maintaining comparable accuracy. The numerical simulation results showed that the diffusion behavior of moisture in packaging structure was guide by the distribution characteristics of moisture-insulating materials. The method could be developed and applied to three-dimensional stacked structures, and the research results could guide the structural layout optimization design of electronic packaging devices for moisture environment resistance.

Key words: high-fidelity finite element modeling method, moisture diffusion, homogenization method