In this study, nano silver (Ag) film was used as the bonding material. High quality bonding layers with low porosity (1.2% to 1.4%) were obtained when the sintering pressure ranged from 5 to 10 MPa at 250 ℃. As the sintering pressure increased from 5 to 10 MPa, the shear strength of the pressure-assisted sintering specimens was improved. The microstructure of the sintered layers was investigated in comparison with the bulk Ag by deep-etching method. The results revealed that the deep-etched morphology of the sintered layer was quite different from that of the bulk Ag. Micron-scale polyhedral Ag grains were observed in the deep-etched morphology of the sintered layers. The grain size and the area of the interfaces between these polyhedral Ag grains changed as the sintering pressure increased from 5 to 10 MPa. This is considered as the dominate factor in the bonding properties of the sintered layers.