Lead Frame Magnetic Current Sensing With High-Voltage Isolation
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Solution Overview
Problem
Current semiconductor packages face challenges in monitoring the operational state of power devices without increasing package size or decreasing performance, particularly in high voltage applications.
Innovation Solution
A semiconductor package design that incorporates a magnetic sensor arrangement 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 and ability to withstand high voltage gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sense circuitry is incorporated into the semiconductor package to monitor operational state, then measurement precision is improved, but device complexity and package size increase
Solution Approach 1:
The patent replaces traditional electrical contact-based current sensing with a magnetic field-based sensing approach. A magnetic sensor detects the magnetic field generated by current flow through the load path, eliminating the need for direct electrical connections between the sensor and the high-voltage power circuit. This substitution of mechanical/electrical contact with magnetic field detection enables current measurement while maintaining package compactness and reducing structural complexity.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the current-carrying load path and the magnetic sensor. Instead of directly measuring current through electrical contact, the sensor measures the magnetic field that mediates the information about current flow. This intermediary approach allows non-intrusive measurement and simplifies the integration architecture within the package.
2Reliability
If electrical isolation is provided between the magnetic sensor and lead frame, then reliability is improved through high voltage tolerance, but device complexity increases
Solution Approach 1:
The patent employs a thin film or layer of electrically insulating material positioned between the magnetic sensor and the lead frame to provide electrical isolation. This thin film structure achieves the required high voltage tolerance and electrical isolation while occupying minimal space and adding minimal structural complexity. The insulating layer acts as a flexible barrier that maintains the compact package design while ensuring reliable high-voltage operation.
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 and high voltage tolerance, addressing the need for efficient state monitoring in high voltage semiconductor packages.
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
Implementation Method 2
an electrical isolation layer that electrically isolates the magnetic current sensor from the lead frame
Data Source
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.