레이저 간섭계(ESPI)에 의해 측정된 플립칩 열변형의 유한요소해석 모델링을 통한 솔더볼의 유동곡선 평가

Abstract

The goal of this study was to determine the uniaxial flow curve for solder balls in a flip-chip from experimental-computational algorithms based on finite element modeling (FEM) of in-plane thermal displacement data measured by electronic speckle pattern interferometry (ESPI). In order to measure the deformation of such tiny components as the solder balls in the flip-chip, the spatial resolution of ESPI was increased to submicron scale by magnifying the areas studied. The flow curve for solder balls in the flip-chip was determined by the algorithm, which effectively matches the simulated solder deformation by FEM to the measured deformation by ESPI. The algorithms were applied to Sn-36Pb-2Ag flip-chip solder balls. The flow curve obtained for flip-chip solder was compared with those for bulk solder. The microstructure was also studied to clarify the flow curve results.