MEMS Inertial Sensor Vibration Isolation Structure
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Solution Overview
Problem
Existing inertia sensors face precision degradation and dysfunction due to external accelerations causing unwanted weight displacement, which is exacerbated by the limitations of current vibration-proof structures in terms of material properties and mounting convenience.
Innovation Solution
A vibration-proof structure with a first vibration-proof part made of silicon rubber sheet and a second part made of silicon adhesive agent or gel, where the second part surrounds the first part, allowing for reduced characteristic frequency and improved mounting convenience by adjusting the shape and Young's modulus to minimize unwanted vibration transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the mass of the vibration-proof structure is increased to lower the characteristic frequency, then the vibration isolation performance is improved, but the dimensions of the sensor increase and material substitution becomes necessary
Solution Approach 1:
The patent uses a composite vibration-proof structure consisting of a soft vibration-proof part (first vibration-proof part) and a hard vibration-proof part (second vibration-proof part). The soft part provides vibration isolation through low stiffness, while the hard part maintains structural integrity and enables compact design. This composite approach allows achieving effective vibration isolation without increasing the overall mass or dimensions of the sensor.
Solution Approach 2:
The patent applies different material properties to different parts of the vibration-proof structure. The first vibration-proof part uses soft material with low Young's modulus for vibration isolation, while the second vibration-proof part uses hard material with high Young's modulus for structural support. This local differentiation of material properties enables effective vibration isolation within a compact form factor.
2Measurement precision
If adhesive agent with low Young's modulus is used to lower characteristic frequency, then vibration isolation is improved, but adhesive flows out during mounting
Solution Approach 1:
The patent uses a soft vibration-proof part made of flexible material that can be formed into a predetermined shape. This flexible structure provides vibration isolation while maintaining structural integrity during mounting, preventing the material from flowing out like conventional liquid adhesives would.
Solution Approach 2:
The patent divides the vibration-proof structure into two distinct parts: a soft vibration-proof part for isolation and a hard vibration-proof part for structural support. The soft part is designed as a separate component with controlled geometry, allowing it to provide vibration isolation without flowing during the mounting process.
3Strength
If the vibration-proof structure is made entirely of hard material, then structural integrity is maintained, but vibration isolation performance deteriorates
Solution Approach 1:
The patent employs a composite structure where the soft vibration-proof part provides vibration isolation and the hard vibration-proof part provides structural integrity. The combination of these two parts with different material properties achieves both vibration isolation performance and structural strength that neither material could achieve alone.
Solution Approach 2:
The patent applies hard material properties to the second vibration-proof part for structural support and hard material properties to the first vibration-proof part for vibration isolation. This local differentiation of material properties enables the structure to simultaneously achieve vibration isolation and structural integrity.
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
This configuration enhances the precision and convenience of inertia sensors by effectively reducing unwanted vibration transmission while maintaining ease of mounting, even in limited packaging spaces.
Implementation Method 1
a first vibration-proof part made of material having a smaller Young's modulus
Implementation Method 2
a second vibration-proof part made of material having a larger Young's modulus than the first vibration-proof part
Implementation Method 3
detecting electrodes for converting the displacements of the weights to electric signals
Implementation Method 4
the periphery of the first vibration-proof part is surrounded by the second vibration-proof part... enabling different characteristic frequencies for improved precision
Data Source
AI summary
Provided is an inertial sensor device comprising a detection part having an MEMS structure, wherein convenience during sensor installation is ensured while erroneous operation caused by the application of external vibration is controlled. To achieve this objective, an anti-vibration structure (103) is provided in the inertial sensor device, between a semiconductor chip (102) mounted on a package substrate and a semiconductor chip (104) comprising a sensor detection part. The anti-vibration structure (103) has a structure in which the periphery of an anti-vibration part (103a) is surrounded by an anti-vibration part (103b) comprising a material having a larger Young's modulus.