3D Magnetic Flux Concentrator Layout for Compact Hall Sensors

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Solution Overview

Problem

Existing magnetic sensor devices face challenges in achieving improved accuracy and reduced size without increasing the size of the semiconductor substrate, while maintaining signal-to-noise ratio and power consumption, while maintaining signal-to-noise ratio and power consumption.

Innovation Solution

The integrated sensor device incorporates a first magnetic flux concentrator aligned with a horizontal Hall element, with specific geometric dimensions to enhance magnetic field measurement accuracy and reduce size, using a semiconductor substrate with a first integrated magnetic flux concentrator aligned with the horizontal Hall element, having a height of at least 30 µm and a height-to-diameter ratio of at least 25%, to improve signal-to-noise ratio and reduce size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the size of the semiconductor substrate is reduced, then the device becomes more compact, but the measurement accuracy and signal-to-noise ratio deteriorate

Engineering Contradiction:
Improvedevice sizeVSAvoidmeasurement accuracy
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent introduces a vertical dimension by placing a magnetic flux concentrator above the Hall element, forming a three-dimensional structure. This allows the device to maintain a compact footprint on the substrate while achieving enhanced magnetic field concentration through the vertical height of the concentrator (at least 30 µm), thereby improving measurement accuracy without increasing substrate area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the geometric parameters of the magnetic flux concentrator, specifically requiring a height of at least 30 µm and a height-to-diameter ratio of at least 25%. These parameter changes optimize the magnetic field concentration effect, enabling improved signal-to-noise ratio and measurement accuracy within a compact device footprint.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a magnetic flux concentrator is added to improve signal-to-noise ratio, then measurement accuracy improves, but device complexity increases

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the magnetic flux concentrator with the Hall element structure, positioning it directly above the Hall element in an integrated configuration. This combining approach improves the signal-to-noise ratio through enhanced magnetic field concentration while minimizing the increase in device complexity by integrating rather than adding separate components.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If the height of the magnetic flux concentrator is increased to improve magnetic field concentration, then signal-to-noise ratio improves, but manufacturing difficulty increases

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoidmanufacturing difficulty
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent specifies optimized parameter ranges for the magnetic flux concentrator, including a height of at least 30 µm and a height-to-diameter ratio of at least 25%. These parameter changes achieve effective magnetic field concentration while remaining compatible with standard semiconductor manufacturing processes, thereby balancing performance improvement with manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

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 integrated sensor device achieves improved accuracy and reduced size by enhancing the signal-to-noise ratio and reducing power consumption, while maintaining a compact form factor.

Implementation Method 1

a first integrated magnetic flux concentrator (iMFC) located above said first horizontal Hall element; wherein the iMFC has a shape with a geometric centre which is aligned with a geometric centre of the horizontal Hall element

Methodology Applied
Scientific EffectMagnetic flux concentration: Magnetic Field

Implementation Method 2

a first horizontal Hall element... configured for providing a signal indicative of a magnetic field component oriented perpendicular to the semiconductor substrate

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP3992652B1Magnetic sensor device
Publication Date: 2026.04.15 MELEXIS TECHNOLOGIES SA
  • EP3992652B1 patent drawingFigure 1(a)~1(c)
  • EP3992652B1 patent drawingFigure 2(a)~2(c)
  • EP3992652B1 patent drawingFigure 3

AI summary

An integrated sensor device (920; 970; 1070) comprising: a semiconductor substrate comprising a horizontal Hall element (Hc), and an integrated magnetic flux concentrator (911; 1011) located substantially above said horizontal Hall element (Hc), wherein the first magnetic flux concentrator has a shape with a geometric center which is aligned with a geometric centre of the horizontal Hall element; and wherein the shape has a height (H) and a transversal dimension (D), wherein H ≥ 30 µm and/or wherein using the largest transversal dimension (H/D) ≥ 0.25 (25%). The integrated magnetic flux concentrator may be partially incorporated in the "interconnection stack" (1223; 1323). A method of producing such an integrated sensor device.