Pressureless and low-temperature sinter-joining on bare Si, SiC and GaN by a Ag flake paste

In this work, we applied a Ag flake formed paste for sinter-joining on bare Si, SiC, and GaN surfaces. The sintered joints possess a high shear strength of over 40 MPa under a pressureless sintering condition at 250 degrees C. The high bonding strength of the joints is achieved by a tight adhesion between Ag and bare surfaces, which attributed to an excellent sinter-joining ability of the Ag flake. The flakes, acquired by mechanical milling, can be rapidly sintered into a homogenous porous structure at a pleasureless and low-temperature sintering condition due to its dislocation-rich nano grain structure. During sintering, a drastic morphology reconstruction of Ag flake, from a flattened flake to a drop-like particle, can introduce robust interfacial connection structures, which is important for the robust bonding. This Ag flake paste can be regarded as a promising sinter-joining material for the connection of bare surfaces in high temperature applications. (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The Ag flake formed paste demonstrates high shear strength sinter-joining on bare Si, SiC, and GaN surfaces, due to its excellent sinter-joining ability and tight adhesion. The mechanical milling-acquired flakes can be rapidly sintered into a porous structure under low-temperature conditions, with drastic morphology reconstruction during sintering introducing robust interfacial connection structures. This promising sinter-joining material is suitable for high temperature applications involving the connection of bare surfaces.