SIMEIT-project: High precision inertial sensor integration on a modular 3D-Interposer platform

The applications of inertial sensors have a wide variety in terms of accuracy and costs. A new technology approach is joining higher sensor accuracy and lower production costs by using a new Interposer / sensor interconnect technology applied on 300mm wafer diameter without changing the sensor element itself. The higher accuracy is mainly covered by a multiple point program: (1) stress less assembly due interface silicon Interposer to silicon MEMS; (2) better Signal to Noise Ratio (SNR) by polymer redistribution layer on the interposer (due to better wiring geometry and less parasitic capacities / inductivities); (3) reduction of mechanical stress by using flexible bar springs for mechanical decoupling of sensor and Interposer substrate; (4) additional stress reduction by using a polymer layer for mechanical decoupling of metal redistribution layer (RDL) and Interposer substrate. The cost efficiency even in small scale serial production based on: (1) 300mm multi project wafer technology including warehouse ready system packaging; (2) a new MEMS contact technology, which gives technical benefit, smaller dimensions and simplifies the assembly of MEMS and ASIC (which are placed on a 2.5D-Interposer in order to enable a System In Package (SiP) as well as for higher sensor accuracy); (3) the flexible ASIC feature enables the integration of different MEMS with analogue signal output; (4) minor costs for integration of different sensors into the existing package. The heterogeneous 3D integration is a key enabler and justifies the additional process steps (mainly TSV-processing, thin wafer handling) by implementing the advantages of the polymer RDL. This integration approach results leads to improved mechanical and electrical properties. This paper will give an overview about the current achievements in the SIMEIT-project, which are predestined to improve the accuracy of different MEMS-applications with analogue signal transfer to the ASIC as well as MEMS-applications with need of stress less integration.