Thermo-mechanical and flexural behavior of WB-PBGA package using moire interferometry

Thermo-mechanical and flexural behavior of a wire-bond plastic ball grid array (WB-PBGA) package assembly is characterized using high-sensitivity moire interferometry. Using the real-time moire setup, fringe patterns are recorded and analyzed at several bending loads and temperatures. Detailed global and local deformations of the assembly are investigated. The deformations caused by thermally induced bending were compared with those caused by mechanical bending. The results reveal highly nonlinear behavior of the package assembly under thermal loading. The sign (direction) of the shear strain caused by the mechanical bending was the opposite of that caused by the thermal load. The results also show that real-time moire interferometry is a powerful and effective tool in experimental studies of electronic packaging