Fluxless pressure Ag sintering in creation of Au-Ag connection systems

This work presents the results of manufacturing of connections based on Au-Ag metallization scheme. This type of connection is made without application of flux, thus no flux cleaning step is required. Such Au - Ag metallization scheme was chosen to simulate similar conditions as in assembly of SiC or GaN devices. Experiment was made to test various conditions of process and pick most satisfying values of time and temperature. Mechanical properties of joints were tested. The highest shear strength was achieved for GaN assembled to DBC substrate with 1 μm Sn layer by Ag sintering at 280 °C and 30 min. Additionally high current tests were performed on Cu ribbon (Ag plated) connections. No degradation was observed for current as high as 80 A/mm
²
.