Numerical Simulation of Top Metal Thickness on IMD Stress due to Probing

Harsh wafer level probing has a higher chance of causing inter metal dielectric (IMD) cracking compared to wire bonding. This work explores the stress induced by probing by utilizing dynamic Finite Element Analysis (FEA) structural mechanics simulation. A thicker bond pad (METTHK with thickness of 3000 nm) can reduce the IMD stress caused by harsh wafer level probing.

Mission critical applications often demand higher reliability under harsh conditions (Weide-Zaage, 2017). As semiconductor devices get more complex, there is often a need to start placing circuits underneath the bond pad (Ker et al., 2003). Reliability of these circuits is often compromised during wire bonding as well as harsh probing. The failures are often associated with dielectric cracking. It is important to understand the material properties and the boundary conditions involved in the probing process.