Sinter materials for broad process windows in DCB packages - concepts and results

Pressure sintering is now an established process technology in DCB applications. The low temperature joining technology (LTJT) process was described by Semikron, TU Braunschweig. A broad rollout of this technology is hindered by numerous design and process constraints: It is not compatible in the many package designs with pressure and temperature sensitive module components; It requires special sintering equipment with low throughput for high pressure sintering; It is compatible only with NiAu finish, whereas cheaper copper, nickel or aluminium surfaces are common; It is not compatible with every die type. This was the motivation for Heraeus to develop sinter materials that meet the requirement of a wide process and application window. Heraeus developed a sinter product platform that is based on micro silver particles. Sinter pastes are suitable for high power density modules and a new class of sinter adhesives, which can be processed like conventional adhesives and used as a solder replacement material in low and medium power density modules. Sinter adhesive joints exhibit similar electrical and thermal properties and increased reliability compared to leadfree solders.