Material Characterization and Modelling for FE-Based Reliability Assessment of PCBs and Electronic Systems

Thermo-mechanical reliability of ECS in general and PCBs in particular is mainly driven by the physical and mechanical behaviour of the applied materials and the mismatch in the properties of those materials. Thus, to create products that feature reliability by design, a detailed know-how of material properties is required mandatorily. This chapter provides an overview on the current situation regarding materials and the availability of material data for base materials of PCBs. A suggestion for data to be considered for material models that are suitable for FEA-based reliability predictions is provided and discussed. A set of (test) methods for characterization of the required material properties data is proposed. In order to substantiate the need of advanced and representative material data, a comparison of the quality of the results from two different FEA is presented. Based on a ten-layer HDI board for a “Machine to X” communication module (M2X module), cases for warpage after press and lifetime under cyclic load in hot oil test conditions have been calculated. While the first setup featured literature−/data sheet-based material models, this is compared against a setting with advanced material models featuring temperature-dependent, characterized and fitted material data. The results of the jobs were validated based on demonstrator boards of the respective M2X module board that have been built and analysed for warpage. Additionally, a hot oil test has been carried out for the bare boards. The test results strongly support the requirement for advanced material models for finite elements simulations. Finally, an outlook on needed future activities in the area of material properties and material data for FEA is given.