Reseaerch on Pressureless Sintering Process for 3rd-Generation Semiconductor Packaging Interconnection

Die attach is a significant segment in semiconductor packaging interconnection. While sintering is a crucial technique in die attach. Assisted pressure sintering will not only increase cost, but also complicate process, and more possibly damage chips. Therefore, researchers pay more attention to pressureless sintering so as to sinter at a cheap, simple, and efficient way with high bonding strength, low porosity, high thermal conductivity, and high electrical conductivity. Pressureless sintering by using copper-based solder is a huge challenge for researchers. Copper has a promising development in microelectronics packaging, owning high electrical conductivity, high thermal conductivity, low iron migration, and cheap price. A paste of self-produced copper particles mixed with micron Sn particles was studied in the article. After sintering at 260°C for 60min without assisted pressure, the joint achieved a bonding strength of 6.27MPa. SEM images showed that the microstructure of the joint. The result manifests that copper particles by mixing tin particles has a promising development in semiconductor packaging interconnection.