Towards reliable pitch assembly using Cu/Ni/SnAg based interconnects

In this paper, the interconnect for 10μm are evaluated. Two processes for obtaining interconnects for 10μm pitch are compared in terms of reliability. One process yields the interconnects with Ni 3 Sn 4 intermetallic (IMC) joint (interconnect A) while other yields the interconnects with solder joint (interconnect B). To select the best process for the assembly at 10μm pitch, high temperature storage tests are performed at 150°C, 175°C and 200°C for 500hrs. The evolution of the metallurgy for both the interconnects is evaluated. The failure mechanism is determined by measuring the change in resistance. On the basis of mechanism, failure statistic is made. Finally, the obtained results are discussed.