Sensor Upper Lid Si-Glass Composite Vacuum Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sensors using silicon-on-insulator (SOI) substrates and upper lids made of silicon and glass do not meet the increasing demand for higher accuracy and reliability, particularly in vehicle control systems.
Innovation Solution
A sensor design that includes a sensor substrate with a fixed part, a deformable beam, and a weight connected to the beam, where the upper lid substrate is composed of silicon and glass, with a projection that protrudes towards the sensor substrate, enhancing the sensor's accuracy and reliability through improved structural integrity and vacuum sealing using Si—Si room-temperature direct bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sensors use traditional sealing structures with silicon and glass upper lids, then manufacturing is relatively simple, but vacuum sealing performance is insufficient and strain occurs at material interfaces
Solution Approach 1:
The upper lid substrate combines silicon and glass materials in a composite structure. The silicon portion provides mechanical strength and bonding capability, while the glass portion provides sealing performance. This composite material approach resolves the contradiction by achieving both improved vacuum sealing and reduced interface strain through compatible material properties.
Solution Approach 2:
The upper lid substrate is divided into distinct silicon and glass portions with a clear interface. The silicon part includes a projection that interfaces with the sensor substrate, while the glass part provides the sealing surface. This segmentation allows each material to perform its optimal function without compromising the other, solving the vacuum sealing problem while maintaining manufacturability.
2Measurement precision
If conventional sensors use standard substrate structures without through-holes, then manufacturing is simpler, but Q-value and signal-to-noise ratio are reduced due to energy loss
Solution Approach 1:
The support layer incorporates through-holes that create a porous structure. These through-holes allow sacrificial material to be removed, creating vacuum pathways that reduce energy loss and improve Q-value. The controlled porosity achieves high measurement precision while the through-holes are formed using standard photolithography and etching processes.
3Reliability
If conventional sensors lack projection structures in the upper lid, then manufacturing is simpler, but vacuum sealing and strain distribution are insufficient
Solution Approach 1:
The silicon portion of the upper lid substrate includes a projection that protrudes toward the sensor substrate before final assembly. This preliminary structural feature is formed during upper lid manufacturing and enables precise alignment and bonding with the sensor substrate, achieving vacuum sealing without requiring complex post-assembly operations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sensor achieves high accuracy and reliability by reducing energy loss, maintaining a high signal-to-noise ratio, and providing a high degree of vacuum sealing, which enhances sensitivity and reduces temperature drift, thus addressing the limitations of existing sensor technologies.
Implementation Method 1
an upper lid substrate including a first part containing silicon and a second part joined to the first part and containing glass
Data Source
AI summary
A sensor includes a sensor substrate, and an upper lid substrate joined to an upper surface of the sensor substrate. The sensor substrate includes a fixed part, a deformable beam connected to the fixed part, and a weight connected to the beam. The weight is movable relative to the fixed part. The upper lid substrate includes a first part containing silicon and a second part joined to the first part and containing glass. The first part includes a projection protruding toward the sensor substrate relative to the second part. The sensor has high accuracy or high reliability.