Development of a Sintering Paste Using Cu@Ag Powder for Power Package

In recent, next-generation power semiconductor materials, such as SiC and GaN, are renowned for their high withstand voltage and low on-resistance characteristics, as opposed to traditional Si-based semiconductors. While extensive research is underway on these advanced power semiconductors, there is also a notable emphasis on investigating bonding materials crucial for connecting semiconductor devices to metal or ceramic substrates. Our attention is particularly drawn to the development of a joining material capable of replacing conventional high-temperature solders, exhibiting superior electrical and thermal conductivity. Sintering bonding, a technology enabling bonding at temperatures comparable to existing high-temperature solder while ensuring high-temperature reliability, has gained prominence. Although sintering bonding with Ag powder is gaining traction, the associated material cost remains a concern. Cu paste, offering a more economical alternative to Ag, faces challenges related to relatively high processing temperature, low bonding strength, and copper oxidation. In our study, we explore pastes for sintering of chip attach and achieve high-strength bonding using Ag coated Cu (Cu@Ag) powder, leveraging the advantages of both materials.