Characterization of High Thermally Conductive Copper–Diamond Joint Obtained by Using Reactive Multilayers and Solder

The temperature evolution during the joining process of high thermally conductive copper-diamond joints was characterized. Experiments and numerical simulations were carried out on the copper-diamond joints, which were joined by using self-propagating reactive multilayers sandwiched by solders. Two different kinds of solders were used, namely Sn-3at%Ag-0.5at%Cu and Sn-9at%Zn. Experimental results showed that the obtained joints had a high shear strength of 32.1 MPa and high thermal conductivity of 38.15 W/(m·K) based upon averages from statistical computations. Numerical simulation results showed that the heat released by the self-propagating reaction of multilayers was quite concentrated. When the reaction finished, the instantaneous temperature of the multilayers had reached nearly 1300 °C. However, the temperature of the copper and diamond never exceeded 400 °C. The heat-affected region of the copper-diamond joint was very localized, and the high-temperature area was mainly distributed within 0.25 mm. There was no significant thermal impact on other nearby components.