Mechanical property changes in sintered silver films by including copper oxide nanoparticles

This paper investigates sintered silver tensile mechanical property changes by adding nano copper oxide particle of approximately 250 nm in diameter. The mixture ratio of polystyrene latex in ultrasonic atomization was adjusted to obtain porous and dense structure. Commercial silver nano paste and fabricated copper oxide nano particles are stirred by changing the copper oxide atomic ratio from 0 to 30 wt%. The paste is sintered at 300 degrees C for 10 min under 60 MPa pressure, and porosity is controlled at approximately 5 %. The stress-strain curves are obtained by quasistatic tensile testing at room temperature and 125 degrees C. At room temperature, stress-strain curves exhibit brittle behaviors irrespective of the copper oxide nano particle ratio. At 125 degrees C, the stress-strain curves change to ductile behaviors, which depend on the copper oxide nano particle ratio. The breaking strain decreases from 10 to 1 %, and the ultimate tensile strength increases from 135 to 280 MPa by changing the copper oxide atomic ratio from 0 to 30 %. This tendency indicates that sintered silver is strengthened by adding the copper oxide nano particles. The die layer reliability is subjected to thermal shocked tests from - 40 to 150 degrees C to evaluate the copper oxide nano particle's strengthening effect on die layer delamination.