Preparation and Low Temperature Sintering of Silver Nanoparticles Based Pastes for Power Semiconductor Device Interaction

The Die-bonding materials of high power semiconductor devices must have excellent heat transfer performance, preeminent thermal cycling stability, outstanding electrical conductivity and the ability to endure high operating temperature. However, the standard solders cannot meet the requirements because of its lower melting point and the environmental regulations, restricting the development of solders. Thus, it is imperative to develop outstanding capability die-bonding materials for power semiconductor device applications. In recent years, silver (Ag) have attracted ever-increasing interest and attentions due to their good stability, as well as excellent thermal and electrical properties. In this work, silver nanoparticles-based paste is demonstrated as a promising lead-free interconnect material for power semiconductor device. Silver nanoparticles with a size of 30-40 nm are synthesized with silver nitrate as precursor, hydrazine hydrate as reducing agent, and lauric acid as capping agent, which are added into terpineol and ethylene glycol to prepare paste based on a lower sintering temperature of silver nanoparticles, a high shear strength of 19.4 MPa can be achieved after sintering at 150 °C and 10 MPa for 30 min. When the sintering temperature increases to 250 °C, the shear strength even reaches 70.2 MPa. The excellent mechanical properties provide a solution for the interaction of power semiconductor device.