Hall Current Sensor Package With Embedded Trace for Higher Accuracy

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional Hall effect current sensors suffer from low sensitivity and accuracy due to the distance between the sensor and the conductive trace, which is exacerbated by noise and complex assembly processes in leadframe-based packages.

Innovation Solution

A method of manufacturing current sensor semiconductor devices where a conductive trace is embedded within the package close to the sensor die, allowing for the design of trace shapes to optimize the magnetic field intensity measured by the Hall sensor, facilitating improved accuracy and sensitivity through concurrent wafer or panel-level processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the sensor is placed farther from the conductive strip to simplify assembly, then assembly complexity is reduced, but measurement precision deteriorates due to lower magnetic field intensity

Engineering Contradiction:
Improveassembly simplicityVSAvoidsensor accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent transitions from external PCB mounting to internal package embedding, moving the conductive trace into a different spatial dimension (inside the package rather than outside). This allows the sensor to be positioned close to the trace while maintaining simple assembly processes through co-packaging of all components.

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

Solution Approach 2:

The patent merges the sensor die, conductive trace, and package into a single integrated unit. By embedding the trace within the package and mounting the sensor die directly above it, all components are combined into one assembly operation, simplifying manufacturing while achieving close proximity for high measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If leadframe-based packages are used to redirect current closer to the sensor, then measurement precision improves, but device complexity increases due to complex assembly techniques

Engineering Contradiction:
Improvesensor accuracyVSAvoidassembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the leadframe component entirely from the conventional design. By removing the leadframe and its complex wire bonding requirements, the design achieves close sensor-trace proximity through direct embedding of the trace in the package, reducing assembly complexity while maintaining measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical leadframe structure with a simplified package-embedded trace design. Instead of using a complex mechanical leadframe system to redirect current, the trace is directly formed and embedded in the package material, substituting a simple fabrication process for a complex mechanical assembly process.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If the conductive trace is embedded closer to the sensor die, then measurement precision improves, but manufacturing complexity increases

Engineering Contradiction:
Improvesensor accuracyVSAvoidmanufacturing process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The conductive trace is preliminarily formed and embedded in the package material before the sensor die is mounted. This preliminary preparation of the trace position and geometry allows the sensor to be subsequently placed in optimal proximity without requiring complex post-assembly adjustments or operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The package material serves multiple functions: it provides mechanical protection, electrical insulation, and a substrate for embedding the conductive trace. This multi-functionality simplifies manufacturing by combining several roles into a single component, reducing overall process complexity while enabling close sensor-trace integration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 approach enhances the accuracy and sensitivity of current measurements by reducing noise interference and simplifying the assembly process, while allowing for flexible adjustment of magnetic field intensity to suit various current measurement applications.

Implementation Method 1

Solutions as described herein can be applied to current sensor integrated circuit (IC) semiconductor devices based on Hall effect

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP4443174A1Current measurement device, corresponding manufacturing method and method of use
Publication Date: 2024.10.09 STMICROELECTRONICS INT NV
  • EP4443174A1 patent drawingFigure 1A~1C
  • EP4443174A1 patent drawingFigure 1D~1E
  • EP4443174A1 patent drawingFigure 1F~1G

AI summary

An integrated circuit current sensing device (10), comprises an insulating encapsulation (20) that encapsulates a semiconductor die (14) having integrated therein a Hall current sensor (HS) configured to measure an electric current (I) flowing adjacent an active surface of the semiconductor die (14). Embedded in the insulating encapsulation (20) there is provided an electrically conductive trace (100) having opposed ends providing therebetween a current flow path adjacent the active surface of the semiconductor die (14). First electrically conductive formations (101) extend through the insulating encapsulation (20) towards the opposed ends of the electrically conductive trace (100) embedded in the insulating encapsulation (20, 20', 20"). The first electrically conductive formations (101) are configured to cause (101) an electrical current subject to measurement to flow in the aforesaid current flow path adjacent the active surface of the semiconductor die (14). Second electrically conductive formations (182, 120, 121) extend through the insulating encapsulation (20) towards the active surface of the semiconductor die (14), the second electrically conductive formations (181, 182, 121) are configured to activate the Hall current sensor (HS) integrated in the semiconductor die (14).