Redundant Wheel Speed Sensor Housing to Block Crack Propagation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Redundant wheel speed sensors in vehicles are susceptible to cracking or fracturing due to overmolding, which can compromise the redundancy and fail-safe operations, especially in autonomous driving applications.
Innovation Solution
A wheel sensor arrangement with a first and second semiconductor die, galvanically isolated from each other, is enclosed in a mold housing with a separation feature that acts as a mechanical barrier to prevent damage from spreading between the sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If redundant wheel speed sensors are integrated into a single overmolded package, then device complexity is reduced and space is saved, but the sensors become susceptible to cracking or fracturing that compromises redundancy
Solution Approach 1:
The mold housing is segmented into a first housing portion and a second housing portion with a separation feature between them. This segmentation physically divides the housing structure so that cracks or fractures in one portion do not propagate to the other portion, thereby protecting the redundant sensors while maintaining the integrated package design
Solution Approach 2:
The separation feature acts as an intermediary barrier between the two sensor components. This intermediate structure prevents direct transmission of mechanical stress and crack propagation between the first and second sensors, preserving redundancy while allowing close integration
2Volume of moving object
If semiconductor dies are placed close together in a compact package, then space is saved and integration is improved, but crack propagation between dies becomes more likely
Solution Approach 1:
The housing is divided into distinct portions with a separation feature that creates physical barriers between closely spaced semiconductor dies. This allows compact packaging while preventing crack propagation between adjacent components
Solution Approach 2:
The separation feature creates a localized region with different structural properties (discontinuity) between the two housing portions. This local structural modification specifically addresses crack propagation risk in the critical interface region while maintaining overall compact dimensions
Data Source
AI summary
A wheel sensor arrangement can include a first wheel speed sensor and a second wheel speed sensor. The first wheel speed sensor can include or be implemented with a first semiconductor die and can provide data regarding a speed of a rotating wheel. The second wheel speed sensor can also include or be implemented with a second semiconductor die and can provide data regarding the speed of the rotating wheel. The second semiconductor die can be galvanically isolated from the first semiconductor die. The wheel sensor arrangement can include a mold housing that forms around the first wheel speed sensor and the second wheel speed sensor. The mold housing can include a separation feature between the first sensor and the second sensor.