In this research, phase shifting method is used to modify PEMI(Portable Engineering Moire Interferometer) into micro moire interferometer which can measure displacement field with highly improved sensitivity. Apart from existing micro moire technique, a low cost and less precise translation stage with rough resolution(10㎛ resolution) is adapted for the phase shifter. Moreover, specimen grating instead of reference grating is phase shifted and again the cost is outstandingly reduced. Least square algorithm is applied to minimize the errors induced by lowering the cost.
To verify the newly constructed micro moire technique, displacement field of Ultra CSP and solder specimen was measured. For Ultra CSP, microscopic local displacement fields such as ACA layer and underfilled area were obtained with increased sensitivity. For solder specimen, displacement field of a solder ball with 300㎛ pitch was acquired with predominantly elevated sensitivity of 26nm per fringe.
