Comb-Drive XYZ-microstage with Large Displacements Based on Chip-Level Microassembly

This paper reports the novel design, fabrication, and testing of a chip-level comb-drive XYZ-microstage that produces large displacements into x-, y-, and z-directions. The main parts of the XYZ-microstage, consisting of a combdrive XY-microstage for in-plane actuations, two comb-drive Z-actuators for out-of-plane actuation, and a bottom silicon base substrate, are assembled together based on chiplevel microassembly technology. The Z-actuators are vertically mounted on the grooves of silicon base substrate and kept in place by the support base block. Then, the XY-microstage is mounted onto the Z-actuators. The small pillars supported by mechanical springs in Z-actuator chips are inserted into the holes of XY-microstage. The conductive glue is used to hold the assembled structure of XYZ-microstage after curing, and also to achieve the electrical connections between the pillars in Z-actuators and the outer driving source of the XY-microstage. Therefore, all the bonded wires can be arranged together on Z-actuator chips, for the application of actuation voltages. It is demonstrated that the assembled comb-drive XYZ-microstage can achieve large displacements of 25.2μm in x-direction, 20.4μm in y-direction, and 58.5 ìm in z-direction.