The residual stresses on aluminum wiring in a resonance scanning mirror, which is one of micro electro mechanical systems (MEMS), were measured using a synchrotron radiation source. The aluminum wiring has the width of 40μm and the thickness of 4μm. The aluminum wiring was deposited by a sputtering method on a silicon substrate. The tensile residual stress was occurred on the aluminum wire and it decreased when the fatigue loading was applied. The subgrain was observed on the aluminum wiring after fatigue using micro-beam synchrotron diffraction technique.
