Research on failure mode of conductive adhesive under high temperature aging and temperature shock
In response to the widely used HD-903 modified epoxy resin conductive adhesive in China's aerospace industry,high-temperature aging and temperature shock were used in this study to accelerate the changes of the conductive adhesive in the service environment,thus conducting research on the reliability of the conductive adhesive.During the experiment,the morphology and organization of the conductive adhesive sample were observed,and its volume resistivity and chip shear strength were measured to reflect the inherent changes of the conductive adhesive through changes in its properties.The research results showed that during the aging process at 150℃,the volume resistance of the conductive adhesive first decreased and then continuously increased,while the shear strength of the chip first increased and then decreased.After 5 000 hours of high temperature aging,the volume resistivity increased by 81.0%compared to before aging,and the shear strength of the chip was 56.5%of before aging.After 3 000 temperature shocks,the volume resistivity of the conductive adhesive increased by 77.2%compared to before the test,and the chip shear strength was only 13.8%of before the test.Analysis suggested that conductive adhesive mainly underwent oxidation of silver powder and aging of resin matrix during high temperature aging.On the one hand,this destroyed the interface structure between silver powder and resin matrix.On the other hand,the aging of resin matrix caused severe relaxation,resulting in a significant increase in volume resistivity and a decrease in adhesive strength.During the temperature shock process,due to the difference in thermal expansion coefficients between the conductive adhesive and the chip,as well as Kovar gold-plated substrate,creep and fatigue of the adhesive joint were induced under alternating stress loads.Cracks gradually propagated on the side of the joint near the chip and the side near the substrate,resulting in a significant decrease in joint strength.
electrically conductive adhesivefailure modehigh temperature agingtemperature shock
万方数据
维普
