On-Chip Capacitor Magnetic Sensor for EMC Noise Reduction
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Solution Overview
Problem
Existing magnetic sensors require external decoupling capacitors to enhance EMC and reduce long-wire noise, which increase costs and package size due to the need for additional components and circuit boards.
Innovation Solution
Integration of an on-chip capacitor formed by first and second conductive layers with a dielectric layer over a substrate within the sensor, eliminating the need for external decoupling capacitors and providing capacitive impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external decoupling capacitors are used, then EMC protection and noise reduction are improved, but device complexity and package size increase
Solution Approach 1:
The patent merges the external decoupling capacitor function with the sensor chip itself by forming an on-chip capacitor structure. The capacitor is created using conductive layers (first and second conductive layers) and a dielectric layer that are integrated into the sensor's substrate, eliminating the need for separate external capacitor components and their associated mounting hardware.
Solution Approach 2:
The sensor chip is designed to perform multiple functions: it provides both the magnetic sensing capability and the decoupling capacitor function simultaneously. The conductive layers and dielectric layer structure serves dual purposes as both interconnect/circuit elements and as a functional capacitor for EMC protection, reducing overall system complexity.
2Reliability
If external decoupling capacitors are used, then EMC protection is improved, but manufacturing cost increases
Solution Approach 1:
The manufacturing process integrates capacitor formation into the existing sensor fabrication sequence. The first and second conductive layers and dielectric layer are deposited and patterned using standard semiconductor manufacturing techniques already employed for the sensor itself, eliminating the need for separate capacitor component procurement, placement, and reflow soldering processes.
Solution Approach 2:
The sensor chip manufactures its own decoupling capacitor functionality through integrated conductive and dielectric layers. The device is self-sufficient, requiring no external capacitor components to be supplied, placed, or connected during assembly, thereby reducing both component costs and assembly process costs.
3Object-affected harmful factors
If external decoupling capacitors are used, then noise reduction is improved, but the number of components increases
Solution Approach 1:
The patent combines the capacitor function with the sensor chip's existing conductive interconnect structure. The first conductive layer, dielectric layer, and second conductive layer form a capacitor that is physically integrated into the chip, reducing the total component count by eliminating separate capacitor devices and their mounting structures.
Solution Approach 2:
The conductive layers serve dual purposes: they function as interconnect pathways for the magnetic sensor circuitry and simultaneously form the capacitor plates for noise filtering. This multi-functionality reduces the number of discrete components needed while maintaining both sensing and noise reduction capabilities.
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 solution reduces costs and package size by providing effective EMC protection and capacitance, suitable for various applications including vehicle sensors, while allowing for flexible capacitance and breakdown voltage adjustments.
Implementation Method 1
a dielectric layer is disposed between the first and second conductive layers such that the first and second conductive layers and the dielectric layer form a capacitor
Implementation Method 2
a dielectric layer is disposed between the first and second conductive layers
Data Source
AI summary
In an exemplary embodiment, a method for a magnetic sensor includes forming a first conductive layer over a substrate containing circuitry, forming a dielectric layer over the first conductive layer, forming a second conductive layer over the dielectric layer such that the first conductive layer, the dielectric layer, and the second conductive layer form a first capacitor, and providing first and second terminals, wherein the first terminal is coupled to the first conductive layer and the second terminal is coupled to the second conductive layer.