Intermetallic Phase on the Interface of Ag-Au-PdAl Structure

الملخص EN

Three wires, Au, Cu, and Ag-Au-Pd, were bonded on an Al pad, inducing IMC growth by a 155 hr high temperature storage (HTS) so that the electrical resistance was increased and critical fusing current density (CFCD) decreased.

Observations of the Ag-Au-Pd wire after HTS (0–1000 hr) indicated that IMC between the Ag-Au-Pd wire and Al Pad was divided into three layers: Ag2Al layers above and below the bonding interface and a polycrystal thin layer above the total IMC.

A high percentage of Pd and Au existed in this 200 nm thin layer, and could suppress Al diffusion into the Ag matrix to inhibit IMC growth.

After PCT-1000 hr, a noncontinuous structure still remained between the IMC layer and interface, and the main phase of IMC was (Ag, Au, Pd)2Al with a hexagonal structure.