Abstract
AbstractThermal characterization of a multichips module (MCM) during the initial design stage is computationally intensive. The influence of each design parameter, such as chip size or position, on the thermal performance needs to be performed and solved whether by numerical simulations or experiments. It is time consuming and not economical. Therefore, this work aims at analyzing the thermal characterization of a BGA type MCM package having multichips with different sizes and positions. An approximated but accurate mathematical equation, which can be used to directly characterize chip junction temperature of the planar MCM, is also proposed.In order to attain the objectives, a rigorous three-dimensional (3D) finite element (FE) model for thermal analysis is established using ANSYS program. The accuracy of the FE model in terms of chip junction temperature is substantially validated against a thermal test die measurement. Since the required boundary condition for thermal analyzing MCM package under a natural convection environment is determined by an Infrared (IR) thermometer, based on the JEDEC standard, the heat convection and radiation effects on package surface are fully considered. Also, the uncertainty analysis is used to analyze the maximum uncertainty of the thermal test die measurement. Furthermore, to establish the response surfaces of chip junction temperature with various chip size and positions, this work successfully steps forward into the parametric study and regression analysis by adopting the 3D FE model constructed and the natural convection and radiation heat transfer correlation model used by Chen et al. (2001). After careful examination by the analysis of variance and coefficient of multiple determinations, it is concluded that the response surfaces can effectively and accurately predict the thermal characterization of a planar MCM with different chip sizes and positions. This study can be further extended to analyze the thermal performance and optimization of stacked MCM and should be very helpful in thermal design of MCM package.