Inertial Sensor Terminal Layout for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inertial sensors face challenges in accurately detecting accelerations due to noise interference, particularly because the arrangement of bonding pads makes it unclear which signals are input to and output from which pads, leading to reduced detection signal quality.
Innovation Solution
The inertial sensor design includes a substrate with sensor elements for measuring accelerations in multiple directions, a lid to accommodate these elements, and strategically positioned terminals where input terminals are farther from the lid than detection terminals, minimizing noise interference and improving signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bonding pads are arranged in a staggered manner with outer and inner rings, then the electrical connection between the sensor element and external circuit is established, but the detection signal quality deteriorates due to noise interference from unclear signal routing
Solution Approach 1:
The bonding pads are segmented into distinct functional groups: drive signal input pads, detection signal output pads, and power/ground pads. This segmentation is implemented through separate bonding pad regions on the substrate that correspond to different signal types, allowing clear signal routing and preventing noise interference between different signal paths.
Solution Approach 2:
The substrate acts as an intermediary element that provides dedicated signal paths between the sensor element and external circuitry. By establishing distinct electrical connection regions on the substrate for different signal types, the intermediate connection structure ensures that detection signals are routed away from noise-generating drive signals, thereby maintaining signal integrity.
2Volume of moving object
If the detection terminal is positioned close to the lid for compact design, then the device size is reduced, but noise interference increases and detection accuracy deteriorates
Solution Approach 1:
Different regions of the substrate are assigned different functional qualities: the first bonding pad region for drive signals is positioned to accommodate higher noise tolerance, while the second bonding pad region for detection signals is positioned to minimize noise exposure. This local differentiation of functional zones allows the detection terminal to be positioned optimally for signal quality while maintaining overall compact device dimensions.
Solution Approach 2:
The bonding pad arrangement employs asymmetric positioning where detection signal pads are strategically located at positions that maximize distance from noise sources (such as drive signal pads and the lid structure), rather than symmetric distribution. This asymmetric layout optimizes the detection signal path by minimizing exposure to electromagnetic interference from adjacent structures.
Data Source
AI summary
An inertial sensor includes a substrate, a sensor element provided on the substrate, a lid that covers the sensor element and is bonded to the substrate, and a plurality of terminals positioned outside the lid and electrically coupled to the sensor element, in which the plurality of terminals include an input terminal to which an electrical signal is input and a detection terminal for detecting a signal from the sensor element, and L1>L2, where L1 is a distance between the input terminal and the lid, and L2 is a distance between the detection terminal and the lid.