Preparation of Ag-Cu Nanoparticle Film Using a Dual-Beam Pulsed Laser Deposition for Power Electronic Packaging

Abstract

Ag-Cu nanoparticle, integrating the advantages of Ag and Cu, is a promising material for power electronic packaging. In this work, a novel dual-beam pulsed laser deposition method was proposed to prepare Ag-Cu nanoparticle film with various component ratios, and used for die attach at low temperatures. The as-deposited Ag-Cu nanoparticle film was mainly composed of Ag-Cu solid solution, Ag element, and Cu element, and most of the nanoparticles were in alloying state. The Ag-Cu sintered joint presented a dense microstructure with 10.8 % porosity, and the shear strength of Ag-Cu sintered joints could reach 60 MPa at 250 ℃. The porosity of the Ag-Cu sintered joints increased as adding more Cu in the Ag-Cu nanoparticle film, resulting in a decrease in the interfacial connection ratio and the fracture mode of sintered joints gradually changed from the sintered layer to the mixed sintered layer and interface fracture. The dual-beam pulsed laser deposition method could guide in designing the component ratios of bimetallic nanoparticles.

Keywords: Dual-beam pulsed laser deposition, Ag-Cu nanoparticle film, Power electronic packaging, Sintering, Low-temperature bonding