Pressureless Direct Bonding of Au Metallized Substrate with Si Chips by Micro-Ag Particles

The aim of this work is to develop and investigate bare Si chips assembly to Au plated substrates. In this research thermal interface material paste based on mixture of micro-Ag particles and pressureless sintering at 175 °C was studied. Joints obtained in the experiments had adhesion of 10 MPa and thermal resistance as low as 0.25 K/W. Novelty of this work is application of micro-Ag paste at low temperature process and without pressure applied on the chip. Those parameters are usually shown as limitation of Ag paste applications. Additionally, after ageing for 500 h at 125°C and thermal cycles (-20°C ÷ 100°C) investigated joints maintained their mechanical and thermal properties.