Abstract
This thesis introduces the applied requirements of the micro scanning mirror firstly. The mechanical designs of the micro scanning mirror based on optical considerations are proposed, including double-side electroplating design, embedded magnetic material design and compound electromagnetic actuating force design. The double-side electroplating design has two merits: (1) the ferromagnetic material is patterned to slender shape to increase the magnetization strength, (2) the backside selective electroplating of the ferromagnetic film increases the volume of the ferromagnetic materials. The embedded magnetic material design has three merits, (1) the Si-Ni compound actuating frame provides superior mechanical properties and large magnetostatic force, (2) the embedded Ni structures not only increase the ferromagnetic material volume but also enhance magnetization strength to enlarge magnetostatic torque, (3) the axial symmetric Si-Ni compound structures can increase the motion stability. The compound electromagnetic actuating force design has two merits: (1) integrate Lorentz force and magnetostatic force to realize the compound actuation, (2) employ the 3D magnet array to get the large concentrated magnetic field. In order to implement the proposed design, the fabrication techniques of double-side electroplating technique and embedded magnetic material are developed. The double-side electroplating technique has two merits: (1) the handle-layer is exploited as the shadow mask to pattern the seed-layer at the backside of the device layer, (2) the device layer acts as the cathode to enable simultaneous double-side electroplating. The embedded magnetic material technique employs a Si mold to simultaneously electroplate and pattern thick Ni to fabricate Si-Ni compound structures. The measurement results successfully demonstrate the proposed designs. In applications, the micro scanning mirrors are used to project 2D Lissajous patterns and raster scan patterns. Moreover, the micro scanning mirrors are operated with pulse laser to verify the system integration. The test results show the device characteristics are sufficient to satisfy the basic requirements of laser scanning display systems.