Research On Technology Of MEMS Wafer Level Vacuum Packaging Based On TGV

TGV(Through Glass Via)is a new interconnected technology,providing 3-dimensional packaging a new way.A new method of TGV based on double-sided glass reflow process is proposed,and applying the new method in wafer level vacuum packaging for gyroscope.The content includes:1.The research background and respectively researches the foreign and domestic methods of wafer level vacuum packaging are introduced.By summarizing the advantage and disadvantage of different methods,developing wafer level vacuum packaging is significant.And TGV technique used in wafer level vacuum packaging is proposed.2.The double-sided glass reflow process is used in TGV technique.The theoretical model of glass reflow is established.To eliminate the thermal stress during the fabrication of TGV substrate,an annealing process is needed.In the last,the electrical properties of vertical feedthroughs are analyzed.3.Through simulation and analysis,the TGV substrate size is finally determined.To obtain suitable processing data of double-sided glass reflow process,a series of experiments with different process parameters were carried out,including temperature,time and the size of silicon mold.Then expounding the important processing of TGV substrate,and accomplishing fabrication of the substrate.4.Based on TGV technique,a wafer level vacuum packaging for gyroscope is proposed.Through simulation and analysis,the size of structure wafer and capping wafer is finally determined.The wafer level vacuum packaging is achieved by studying on the bonding technology.5.The performances of the packaged prototype are tested.The electrical conductive of vertical feedthroughs are proved good enough.And the bonding strength is 7.28 MPa,it proves the bonding process is feasible.Furthermore,through testing the quality factors of packaged prototype,the vacuum degree of the seal cavity is about 200 Pa-240 Pa,demonstrating the packaged prototype is successful.