Through-Wafer Vias for Reliable MEMS Sensor Encapsulation
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Solution Overview
Problem
Current semiconductor devices with MEMS sensors face compatibility issues due to fragility and imperfect sealing when integrating electrical connections through caps, leading to conductivity problems and incomplete encapsulation.
Innovation Solution
The method involves forming through-wafer conductive vias in a semiconductor substrate by creating trenches, lining them with dielectric material, filling with conductive material, and sealing with a cap to encapsulate electrical components, ensuring electrical isolation and a secure connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical leads are run across the surface of the substrate from the MEMS sensor, then electrical connection is achieved, but the interface between the cap and electrical connector leads to imperfect seal or conductivity problems
Solution Approach 1:
The patent introduces conductive vias as an intermediary structure that passes through the substrate to provide electrical connection. This mediator eliminates the need for surface-level electrical connectors that interface with the cap, thereby resolving the seal and conductivity problems at the cap-interface region.
Solution Approach 2:
The patent transitions the electrical connection from a two-dimensional surface route to a three-dimensional through-substrate via. By routing electrical connections vertically through the substrate rather than horizontally across the surface, the cap interface is simplified and seal integrity is improved.
2Reliability
If through-wafer conductive vias are formed using external fill processes, then electrical isolation and conductivity are achieved, but manufacturing complexity and process steps increase
Solution Approach 1:
The patent enables the substrate material itself to form the conductive vias through controlled doping during substrate fabrication. This self-service approach eliminates the need for external fill processes, reducing manufacturing complexity while achieving the required electrical isolation and conductivity.
Solution Approach 2:
The patent incorporates via formation into the substrate fabrication process itself, performing the electrical isolation and conductivity setup in advance during substrate manufacturing. This preliminary action eliminates subsequent fill processes and simplifies the overall manufacturing workflow.
Data Source
AI summary
A method of manufacturing a semiconductor device includes providing a semiconductor substrate having first and second main surfaces opposite to each other. A trench is formed in the semiconductor substrate at the first main surface. The trench extends to a first depth position in the semiconductor substrate. The trench is lined with the dielectric material. The trench is filled with a conductive material. An electrical component is electrically connected to the conductive material exposed at the first main surface. A cap is mounted to the first main surface. The cap encloses the electrical component and the electrical connection.