Lead Frame Current Sensing for Compact High-Voltage Packages

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Solution Overview

Problem

Current semiconductor packages face challenges in monitoring the operational state of high voltage power devices without increasing package size or decreasing performance, as existing solutions require larger sizes or compromised performance.

Innovation Solution

A semiconductor package with a magnetic sensor arrangement mounted directly on the lead frame, which includes a magnetic current sensor and an electrical isolation layer, allowing for accurate current measurement with minimal impact on package size, suitable for high voltage loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sense circuitry is incorporated into the semiconductor package to monitor operational state, then measurement precision is improved, but package size increases

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoidpackage size
Core Design Contradiction:
Measurement precisionVSVolume of stationary object

Solution Approach 1:

The magnetic sensor arrangement is integrated directly onto the lead frame structure, merging the sensing function with the existing mechanical support structure. This eliminates the need for separate sensing components and reduces overall package volume while maintaining measurement capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lead frame serves multiple functions: it provides mechanical support, electrical connections, and now also serves as the mounting substrate for the magnetic sensor arrangement. This multi-functionality reduces the need for additional components and minimizes package size.

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

2Measurement precision

If sense circuitry is incorporated into the semiconductor package to monitor operational state, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoidpackage structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The magnetic sensor arrangement combines the magnetic current sensor and electrical isolation layer into a single integrated component mounted on the lead frame. This merging reduces the number of discrete parts and simplifies the overall package structure while maintaining measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The electrical isolation layer acts as an intermediary between the magnetic current sensor and the lead frame, providing necessary electrical isolation while maintaining a simple two-layer structure. This approach avoids complex isolation schemes while ensuring proper electrical separation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 accurate monitoring of load current with minimal package size impact, effectively addressing the need for operational state monitoring in high voltage semiconductor devices.

Implementation Method 1

a magnetic sensor arrangement mounted directly on a region of the lead frame which forms part of the load path connection, wherein the magnetic sensor arrangement comprises a magnetic current sensor that is configured to measure a current flowing through the load path connection

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP4376073A1Semiconductor package with current sensing
Publication Date: 2024.05.29 INFINEON TECH AUSTRIA AG
  • EP4376073A1 patent drawingFigure 1A~1B
  • EP4376073A1 patent drawingFigure 1C~1D
  • EP4376073A1 patent drawingFigure 2A~2B

AI summary

A semiconductor package includes a lead frame that includes a die pad and a first lead extending away from the die pad, a semiconductor die mounted on the die pad, a load path connection that electrically connects a first load terminal of the semiconductor die with the first lead, and a magnetic sensor arrangement mounted directly on a region of the lead frame which forms part of the load path connection, wherein the magnetic sensor arrangement comprises a magnetic current sensor that is configured to measure a current flowing through the load path connection and an electrical isolation layer that electrically isolates the magnetic current sensor from the lead frame.