Abstract: A method for packaging micromachined devices fabricated by MEMS and semiconductor process is disclosed in this invention. The method employed etching technique to etch a trench surrounding the micromachined components on each chip of the first wafer down to the bottom interconnection metal layer. The said trench can accommodate the solder of flip-chip packaging. On each chip of the second wafer, or called as the second chip, a surrounding copper pillar wall corresponding to the trench on the first chip is deposited. By wafer-level packaging, the trench on the first chip is aligned to the pillar wall, and then bonded together with elevated temperature. The face-to-face chamber formed between two chips can allow the movement of the micromachined structures. Further, the signal or power connections between two chips can be established by providing several discrete pillar bumps.

Abstract: This invention disclosed a method to strengthen structure and enhance sensitivity for CMOS-MEMS micro-machined devices which include micro-motion sensor, micro-actuator and RF switch. The steps of the said method contain defining deposited region by metal and passivation layer, forming a cavity for depositing metal structure by lithography process, depositing metal structure on the top metal layer of micromachined structure by Electroless plating, polishing process and etching process. The method aims at strengthening structures and minimizing CMOS-MEMS device size. Furthermore, this method can also be applied to inertia sensors such as accelerometer or gyroscope, which can enhance sensitivity and capacitive value, and deal with curl issues for suspended CMOS-MEMS devices.

Abstract: A method for packaging micromachined devices fabricated by MEMS and semiconductor process is disclosed in this invention. The method employed etching technique to etch a trench surrounding the micromachined components on each chip of the first wafer down to the bottom interconnection metal layer. The said trench can accommodate the solder of flip-chip packaging. On each chip of the second wafer, or called as the second chip, a surrounding copper pillar wall corresponding to the trench on the first chip is deposited. By wafer-level packaging, the trench on the first chip is aligned to the pillar wall, and then bonded together with elevated temperature. The face-to-face chamber formed between two chips can allow the movement of the micromachined structures. Further, the signal or power connections between two chips can be established by providing several discrete pillar bumps.