Damage Parameter: Proposed Index to Quantify the Durability of Sintered Nano Silver and Multilayer Aluminum Foil Die Attach

This paper investigates the damage parameter (DP) effectiveness for sintered silver (s-Ag) and multilayer aluminum foil (MAF) die attach degradation by thermal shocked test (TST) and nine-point bending test (NBT). The s-Ag layer consists of a single porous layer, while the MAF consists of multilayers that electroplated Ag layers are deposited on both top surfaces of the Al layer. SiC chips are bonded to substrates by hot-press bonding is implemented in the solid state to achieve enough interface bonding strength. TSTs are conducted under thermal cyclic loading between -40 and 150∘C with the trapezoidal waveform for 60 min per a cycle. NBTs are conducted under cyclic mechanical loading between 0 and 300 N with a triangle waveform for 3 min per a cycle at 150∘C. Scanning acoustic tomography (SAT) evaluates the die delamination after 1000 cycles of TST and NBT. A proposed index with DP effectively works to fit the delamination rate of both s-Ag and MAF after TSTs and NBTs. MAF delamination rate is lower than the s-Ag delamination rate due to MAF's smaller DP than the s-Ag's DP.