Determining mechanical properties of thin film in packaging structures by in-situ nanoindentation

Abstract

With the progress of miniaturization of electronic chips and their packaging structures, miniature electronic equipment is becoming highly integrated. The sizes of packaging materials required for equipment packaging structures is significantly reduced so that the material properties of those small-sized packaging materials cannot be measured using the conventional testing methods. Therefore, new technologies are greatly expected to utilized to measure the small-sized materials for in-situ packaging structures. Nanoindentation technology is an effective and nondestructive method for the evaluation of the material mechanical properties of thin film materials on substrate such as elastic modulus, hardness, hardening exponent and yield stress at an advanced micro/nano scale because of its easy preparation and high resolution of applied load-penetration depth during indentation stage. Based on the nanoindentation technology, the finite element analysis theory is used to take the simulation of the mechanical behavior of thin film material in in-situ equipment packaging structure subjected to single-point nanoindentation with loading and unloading. In addition, the two-dimensional nanoindentation finite element model is used for simulation and fitting the dimensionless equation. Then, dimensionless equations are constructed through the dimensional analysis theory from the applied load-penetration depth curve to analyze the factors which can affect the constitutive parameters of the thin film based on the finite element simulation. Finally, the three-dimensional nanoindentation finite element model is used for the verification of theory for solving constitutive parameters of thin film.