Meaning
Thermomechanical joining process that uses external pressure and heat to fuse copper particles into a solid, highly conductive interface. Press copper sintering provides an alternative to traditional soldering for power electronics that operate at extremely high temperatures. The process creates a bond with high melting points and superior thermal conductivity, making it suitable for electric vehicle inverters and wide-bandgap semiconductors.
Mechanism Description
Mechanical force drives the copper particles into close contact while heat initiates the diffusion of atoms across the grain boundaries. During press copper sintering, the application of ten to thirty megapascals of pressure overcomes the surface tension of the metal. This physical compression eliminates the need for the extremely high temperatures that would otherwise be required to melt bulk copper.
Yield Factor
Surface finish on the substrate and the die directly influences the quality of the resulting bond.
Operational Limit
High pressure requirements necessitate specialized hydraulic or servo-driven equipment that can maintain uniform force across the entire wafer. If the pressure is uneven, press copper sintering produces localized weak spots that may fail under vibration. The tooling must be designed to accommodate the slight variations in die thickness to prevent mechanical cracking of the silicon during the cycle.
