چكيده به لاتين
Abstract:
An Integrated Circuit is a set of electronic circuits on small flat piece of a semiconducting material.These devices are usually made up a composite of different layers. According to their importance and effectiveness and also the time and money that are spent on their production, detection of destructive factors, and finding a solution for removing or reducing them, seem to be necessary and important.
One of the factors that plays a major role in the failiure of these products, is residual stress. These stresses are inside the devices and trapped and while the device is not under any type of load, some parts of its resistance spend to overcome these tensions. In this study, to determine the residual stress that are trapped in these devices, numerical and experimental studies have been conducted. At first, residual stress fields of two Integrated Circuit, Ball Grid Array and Thin Quad Flat Package, were obtained by numerical simulation of the macroscopic stress. Then due to the viscoelastic properties of one of the layers, the comparison between numerical results of the simulations of viscoelastic and elastic state, has been done. After this, to calculate the experimental residual stresses beacause of the limitations and characteristics of ball grid array integrated circuit, incremental hole drilling method was selected as a proper method. Finally, the obtained residual stresses results from experimental strains and calibration coefficients were compared with the results of the simulations. As respects that experimental and numerical results are in good agreement with each other so, numerical simulation results can be used to identify sensitive points and failure analysis in future works.
Keywords: Integrated Circuit, residual stresse, viscoelastic material, incremental hole drilling method
