Physical Quantity Sensor Stress Isolation via Intermediary Substrate
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Solution Overview
Problem
Existing physical quantity sensors, such as vibration type gyro sensors, face issues with detection accuracy due to stress transmission from the package base, leading to changes in zero-point output when not detecting angular velocity.
Innovation Solution
A physical quantity sensor design that includes a supporting member, such as a relay substrate, interposed between the package and the sensor element, which reduces stress transmission and improves detection accuracy by optimizing the layout of detection and drive signal wirings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the vibrator element is directly fixed to the package base, then the structure is simple and easy to manufacture, but stress such as thermal stress generated in the package base is transmitted to the vibrator element causing zero point output drift
Solution Approach 1:
A supporting member is introduced as an intermediary component between the package base and the vibrator element. This supporting member isolates the vibrator element from stress transmitted by the package base, thereby preventing zero point output drift while maintaining manufacturing simplicity through a modular addition rather than redesigning the entire structure.
2Difficulty of detecting and measuring
If detection signal electrodes are formed in the first and second detection arms, then detection capability is provided, but stress transmission from package base causes output drift when not receiving angular velocity
Solution Approach 1:
The supporting member serves as a mediator that decouples the detection signal generation function from the stress-prone package base structure. The detection signal electrodes remain functional in the detection arms while the supporting member prevents stress-induced output drift, thereby maintaining both detection capability and signal accuracy.
3Measurement precision
If the supporting member includes a substrate with detection signal wirings intersecting the drive signal wiring, then noise interference is minimized through optimized wiring layout, but the structure becomes more complex
Solution Approach 1:
The detection signal wirings are routed along a second axis that intersects with the drive signal wiring along the first axis, creating a dimensional separation in the wiring layout. This orthogonal arrangement minimizes parallel coupling and noise interference between signal lines while the supporting member integrates these wirings into a unified substrate structure, balancing complexity reduction with noise immunity.
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 solution enhances detection accuracy by minimizing noise interference and capacitance differences, allowing for high sensitivity and improved performance in detecting angular velocity.
Implementation Method 1
a vibration type gyro sensor using a piezoelectric body such as a vibrator element
Implementation Method 2
a vibration type gyro sensor using a piezoelectric body such as a vibrator element
Data Source
AI summary
A physical quantity sensor includes: a supporting member; and a sensor element supported by the supporting member, in which the sensor element includes a vibrator element, a drive signal wiring disposed on the vibrator element, and a first detection signal terminal and a second detection signal terminal disposed on the vibrator element, the supporting member includes a substrate on which the sensor element is joined, and a first detection signal wiring and a second detection signal wiring disposed on the substrate, and the first detection signal wiring and the second detection signal wiring respectively include areas that extend along a second axis intersecting with the first axis and that intersect with the drive signal wiring in a plan view as seen in a direction in which the sensor element and the substrate overlap with each other.