Thermomechanical and Flexural Behavior of WB-PBGA Package Using $Moir{\acute{e}}$ Interferometry

모아레 간섭계를 이용한 WB-PBGA 패키지의 온도변화 및 굽힘하중에 대한 거동해석

Thermo-mechanical and flexural behavior of a wire-bond plastic ball grid array (WB-PBGA) are characterized by high sensitive $moir{\acute{e}}$ interferometry. $Moir{\acute{e}}$ fringe patterns are recorded and analyzed at several various bending loads and temperature steps. At the temperature higher that $100^{\circ}C$, the inelastic deformation in solder balls became more dominant. As a result the bending of the molding compound decreased while temperature increased. The strain results show that the solder ball located at the edge of the chip has largest shear strain by the thermal load while the maximum average shear strain by the bending moment occurs in the end solder. The results also show that $moir{\acute{e}}$ interferometry is a powerful and effective tool in experimental studies of electronic packaging.