MEMS Microphone Back Chamber Volume via Substrate Nesting

The patent applies nesting by placing the ASIC chip inside a cavity formed within the substrate. This cavity serves dual purposes: it provides space for the ASIC mounting and simultaneously contributes to forming the back chamber volume. The substrate is designed with an internal cavity rather than being solid, allowing the back chamber to extend into the substrate volume. This nested structure enables the back chamber volume to be increased without proportionally increasing the external housing dimensions, as the back chamber utilizes the internal void space of the substrate structure.

The patent transitions from a two-dimensional planar arrangement of components to a three-dimensional spatial configuration. Instead of placing the MEMS chip and ASIC side by side on the substrate surface, the ASIC is positioned inside a cavity within the substrate thickness direction. This vertical stacking arrangement in the third dimension allows both components to coexist within a compact footprint while maximizing the back chamber volume in the horizontal plane, effectively utilizing the substrate's thickness to accommodate multiple functional elements.

The patent merges multiple functions into the substrate structure. The substrate not only serves as the mounting platform for the MEMS chip and ASIC but also incorporates the back chamber cavity and provides electromagnetic shielding through conductive layers. The cavity formation is integrated into the substrate manufacturing process, and the conductive shielding layers are deposited as part of the substrate fabrication sequence. This consolidation of multiple functions into a single substrate component reduces the overall device complexity compared to having separate structures for mounting, chamber formation, and shielding.