Experimental characterizations of the influence of sintering pressure on the high-temperature tensile behavior of sintered silver

Purpose This paper aims to systematically investigate the effect of the sintering pressure on the microstructure and tensile behavior of sintered silver at both room and elevated temperatures. In contrast to earlier studies, this research uniquely explores the combined influence of sintering pressure, strain rate, on the high-temperature mechanical response of the porous sintered silver material. Design/methodology/approach Specimens were manufactured from a microscale silver paste using sintering pressures of 7 and 15 MPa at sintering temperatures of 230 °C for three minutes, to forcibly induce distinct porosity levels. Subsequently, tensile tests were carried out at strain rates of 10−4 and 10−5 s−1, and at room temperature and at 200 °C. Findings The porosity level, as extracted from optical microscopy image analysis, were computed as 24.1% and 14.7% for sintering pressures of 7 and 15 MPa, respectively. In addition, the results indicated that higher sintering pressure, that is, lower porosity, consistently improves mechanical performance across all test configurations. Statistical analysis further reveals that porosity, strain rate and loading temperature collectively govern the mechanical response, with porosity acting as a key microstructural link between processing conditions and material behavior. Notably, thermal effects were found to be more dominant than rate effects. The combined influence of porosity, strain rate, on the high-temperature mechanical properties has been unified in a bilinear isotropic hardening material model and validated with finite element simulations. Originality/value Sintered silver has become a preferred bonding solution for high-performance power electronics due to its outstanding mechanical and thermal properties. Among the various sintering parameters, applied pressure plays a critical role in determining the porosity and, consequently, the mechanical performance of the resulting bond. Although the influence of sintering pressure has been widely studied, its effects remain not fully understood, especially under elevated temperature conditions. Unlike earlier studies, this research has exclusively explored the high-temperature behavior of the sintered silver with various porosity levels. The findings of the present study highlight the importance of explicitly incorporating porosity into constitutive models to enhance the accuracy of finite element simulations for sintered silver joints in power electronic applications.