167 / 2022-03-14 15:07:42

Time-domain evolution of resistance characteristics of nano-copper solder layer based on electric pulse sintering

nano-copper, electric pulse sintering, sample resistance, time-domain evolution, resistance characteristics, prediction model

Nano-copper electric pulse sintering is a new type of rapid chip packaging technology, which has the characteristics of high strength, high temperature resistance and low energy consumption, so it has broad application prospects. This paper focuses on the time-domain evolution of the resistance characteristics of nano-copper sintered samples under the action of electric pulses, and further explains the evolution of the resistance of the samples by means of high-speed photography, shear testing, scanning electron microscopy and other observation methods. The research results show that the resistance of the sample has a good corresponding relationship with the shear strength, that is, the lower the resistance, the greater the shear strength. Under the pulse discharge after the first pulse discharge, the resistance is mainly affected by the Joule heating effect, and the increase rate becomes slower with time. The electric pulse sintering has the optimal number of discharges: when the number of discharges is less than the optimal number, the welding layer becomes denser with the increase of the number of discharges, so that the resistance decreases and the shear strength increases; when the number of times is greater than the optimal number, the welding layer deteriorates It is aggravated with the increase of the number of discharges, resulting in an increase in the resistance and a decrease in the shear strength. Finally, a calculation model of sample resistance is proposed in this paper, which can accurately predict the time-varying characteristics of resistance under the action of electric pulse.