Hybridly Integrated Component With Dual-Sided MEMS On ASIC
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Solution Overview
Problem
Existing hybridly integrated components face challenges in achieving high integration density and effective surface usage when the surface requirement for the MEMS function is significantly greater than that for the ASIC function, leading to inefficient use of chip space and increased production costs.
Innovation Solution
A five-fold wafer stack is created by mounting two MEMS elements with micromechanical structures extending over the entire thickness of their respective substrates on either side of an ASIC element, with a cap wafer sealing the structures to create a compact, hermetically sealed unit that enhances functionality and protects the sensor structures from contamination and environmental influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a single MEMS element is mounted on the ASIC element, then the component achieves basic sensor functionality, but the surface usage efficiency is poor when the MEMS structure requires significantly larger chip surface than the ASIC function
Solution Approach 1:
The patent transitions from a single-sided MEMS configuration to a dual-sided configuration, mounting MEMS elements on both the front side and rear side of the ASIC element. This dimensional change in spatial arrangement allows the micromechanical structures to utilize both surfaces of the ASIC substrate, effectively doubling the functional capacity within the same footprint and significantly improving surface usage efficiency when MEMS structures require larger area than ASIC functions
2Measurement precision
If the micromechanical structure extends over the entire thickness of the MEMS substrate, then the measurement sensitivity is improved, but the chip surface area required increases
Solution Approach 1:
The patent utilizes the third dimension (thickness/depth) by extending micromechanical structures over the entire thickness of the MEMS substrate. This vertical extension into the depth dimension allows the creation of three-dimensional sensor structures such as proof masses and suspension systems that achieve high measurement sensitivity without requiring proportional increases in planar surface area, as the functional volume is exploited rather than just surface area
3Device complexity
If the micromechanical structure is exposed without sealing, then the component structure is simpler, but the sensor signals are affected by environmental influences and contamination
Solution Approach 1:
The patent integrates the sealing function directly into the wafer stack structure by bonding cap wafers to the ASIC element, which in turn supports the MEMS elements. This merging of structural support and environmental sealing functions into a unified stacked architecture protects the micromechanical structures from environmental influences and contamination while maintaining a compact design, rather than adding separate sealing components that would increase overall complexity
Solution Approach 2:
The patent creates a hermetically sealed environment around the micromechanical structures by bonding cap wafers to enclose the MEMS elements within the wafer stack. This sealed enclosure isolates the sensitive sensor structures from external environmental factors such as moisture, dust, and atmospheric pressure changes, providing a controlled and stable operating environment that preserves signal integrity
Data Source
AI summary
A hybridly integrated component includes an ASIC element having a processed front side, a first MEMS element having a micromechanical structure extending over the entire thickness of the first MEMS substrate, and a first cap wafer mounted over the micromechanical structure of the first MEMS element. At least one structural element of the micromechanical structure of the first MEMS element is deflectable, and the first MEMS element is mounted on the processed front side of the ASIC element such that a gap exists between the micromechanical structure and the ASIC element. A second MEMS element is mounted on the rear side of the ASIC element. The micromechanical structure of the second MEMS element extends over the entire thickness of the second MEMS substrate and includes at least one deflectable structural element.