Power Semiconductor Module Current Sensing via Insulated Magnetic Sensor

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Solution Overview

Problem

Existing power semiconductor module arrangements face challenges with large and expensive current measurement systems that generate significant heat and require improvements for efficient and cost-effective current monitoring.

Innovation Solution

Incorporation of a magnetic field sensor on a printed circuit board within the module, galvanically insulated from conducting components, to detect magnetic fields generated by current flow, allowing contactless current measurement without bulky shunts or additional costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional current measurement arrangements are used, then current monitoring is achieved, but the arrangement becomes large, expensive, and generates significant heat

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoidarrangement size and cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical/current-based measurement arrangements with a magnetic field sensor that detects magnetic fields generated by current flow. This substitution eliminates the need for bulky shunts and complex measurement circuits, achieving contactless current measurement while reducing arrangement size and cost.

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

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the current-carrying component and the measurement system. The magnetic field sensor detects the magnetic field generated by current flow through the electrically conducting component, enabling indirect but accurate current measurement without direct electrical contact.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional current measurement arrangements are used, then current monitoring is achieved, but heat generation increases

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoidheat generation
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent replaces traditional current measurement arrangements that generate significant heat with a magnetic field sensor-based system. This substitution eliminates the need for high-power measurement circuits and shunts, dramatically reducing energy loss and heat generation while maintaining measurement capability.

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

3Measurement precision

If magnetic field sensor is placed close to electrically conducting component, then measurement sensitivity improves, but electrical insulation becomes more difficult

Engineering Contradiction:
Improvemagnetic field detection sensitivityVSAvoidelectrical insulation
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent uses the magnetic field as an intermediary that can penetrate through the encapsulant material, allowing the sensor to be placed close to the current-carrying component for high sensitivity while maintaining electrical insulation. The magnetic field passes through the encapsulant without requiring direct electrical contact.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

This principle is not applicable to this patent.

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

Solution Approach 3:

The patent employs an encapsulant material that provides both electrical insulation and magnetic field permeability, creating a composite solution that satisfies both insulation and sensitivity requirements. The encapsulant acts as a barrier to electrical contact while allowing magnetic field transmission.

Inventive Principle:
Principle #40Composite materials

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

Enables compact, efficient, and cost-effective current monitoring by leveraging existing components and insulation methods, reducing heat generation and component size.

Implementation Method 1

a magnetic field sensor (900) arranged on the printed circuit board (81) within the range of a magnetic field caused by a current flowing through one of the electrically conducting components (950), the magnetic field sensor (900) being electrically insulated from the electrically conducting component (950)

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP4280277B1Power semiconductor module arrangement and method for producing a power semiconductor module arrangement
Publication Date: 2026.02.25 INFINEON TECHNOLOGIES AG
  • EP4280277B1 patent drawingFigure 1~2
  • EP4280277B1 patent drawingFigure 3~4
  • EP4280277B1 patent drawingFigure 5~7

AI summary

A power semiconductor module arrangement comprises a housing (7), a substrate (10) comprising a substrate layer (11) and a first metallization layer (111) deposited on a first side of the substrate layer (11), and arranged inside the housing (7) or forming a bottom of the housing (7); a printed circuit board (81) arranged inside the housing (7), vertically above and in parallel to the substrate (10); a plurality of electrically conducting components arranged on the printed circuit board (81) and on the substrate (10), an encapsulant (5) at least partly filling the interior of the housing (7), thereby covering the substrate (10), and a magnetic field sensor (900) configured to detect the strength of a magnetic field; wherein either the magnetic field sensor (900) is arranged on the substrate (10) within the range of a magnetic field caused by a current flowing through one of the electrically conducting components (950) arranged on the printed circuit board (81), or the magnetic field sensor (900) is arranged on the printed circuit board (81) within the range of a magnetic field caused by a current flowing through one of the electrically conducting components (950) arranged on the substrate (10), the magnetic field sensor (900) is electrically insulated from the respective electrically conducting component (950), and the power semiconductor module arrangement further comprises evaluation means configured to determine the current flowing through the electrically conducting component (950) based on the strength of the magnetic field detected by the magnetic field sensor (900).