Mechanical characterization of bond wire materials in electronic devices at elevated temperatures

Today, micro- and power electronic components are used within a rapidly increasing number of different automotive applications playing a key role within power generation and energy conversion systems. As a consequence, particularly the interconnecting materials of electronics systems are extremely challenged by harsh environment conditions like high operational temperatures, which are partially superposed by intensive mechanical loading and high thermo mechanical stresses. In order to meet the robustness and reliability demands required for industrial applications, detailed understanding of the material response regarding (visco-) elastic, plastic or creep deformation behavior as a function of temperature is necessary. In this study, elastic and plastic material properties of bond wire materials at temperatures up to 350°C have been determined by nanoindentation. Using a Voce model to consider the plastic material behavior, the applied material parameter extraction procedure was exemplarily demonstrated for three different heavy bond wire materials as a model system. The test method presented has been validated by comparing results from reference tensile testing with the deformation behavior gained from nanoindentation testing. Thus, the testing method and data evaluation procedure can also be applied to determine local material parameters in critical process- or application-affected regions of microelectronic packaging materials.