Large-scale manufacturing of embedded subsystems-in-substrates and a 3D-stacking approach for a miniaturised medical system integration

This paper brings into light the first prototype miniaturized system-in-package (SiP) Microsystems built for wireless body-area-network medical devices which mandate low power consumption and extreme packaging miniaturization. Specifically, this paper focuses on the scenario for a 3D-SiP module for wearable demonstrators, namely hearing aids and insulin pups, with an active antenna integrated on top of the individual 2D-SiPs. The whole 3D-SiP is assembled on the end-user device PCB. The presented paper describes in detail all manufacturing steps for the realization of the 3D-SiP and all technology developments achieved to reach this goal. Firstly, a 2-layer SiP substrate has been successfully produced with 35 μm ultra fine line copper structuring in conjunction with 100 μm blind vias using semi-additive technology. Subsequently, assembly technologies for heterogeneous BAN components were further developed in order to achieve the placement of the tiny IF SAW filters and BAW resonators on the substrate and to implement mixed assembly of soldered passives with fluxed chip packages. Finally, the paper highlights the embedding technology employed in the project for the manufacturing of 3D-SiP modules on 9"×12" large panels, as well as the stacking technology for the realization of the 3D-SiP microsystems. The whole 3D-SiP module has a very small size of 3.48 mm × 3.48 mm × 1.5 mm.