Power Module Current Sensor Layout for Compact Insulated Sensing
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Solution Overview
Problem
Existing power modules face challenges in integrating current sensors without increasing size or complicating the structure, while maintaining precise current measurement and insulation.
Innovation Solution
The power module incorporates coreless current sensors with magnetoelectric conversion elements and signal processing ICs, arranged between phase terminals and power semiconductors on an insulating substrate, using insulating resin encapsulation to minimize space and maintain insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a current sensor is mounted on a substrate with semiconductor devices, then current measurement function is added, but the module size increases and structure becomes more complex
Solution Approach 1:
The current sensor is integrated directly onto the substrate where semiconductor devices are mounted, combining the sensing function with the existing power module structure. This eliminates separate sensor housings and mounting structures, reducing overall complexity while maintaining measurement precision through direct placement near the conductors.
2Reliability
If insulation structures are added between conductors and current sensor, then insulation reliability is improved, but the module volume increases
Solution Approach 1:
A thin insulating resin layer is applied directly to the substrate surface to provide electrical insulation between the conductors and the current sensor. This thin film approach ensures reliable insulation without requiring bulky discrete insulator components, thereby maintaining compact module volume while achieving the required insulation reliability.
3Measurement precision
If the current sensor is placed close to the conductor for accurate measurement, then measurement precision is improved, but insulation difficulty increases
Solution Approach 1:
The substrate surface serves as an intermediary between the conductor and the current sensor, with a thin insulating resin layer providing the necessary electrical isolation. This intermediary insulation layer enables the current sensor to be positioned close to the conductor for accurate magnetic field detection while maintaining adequate electrical insulation to prevent short circuits.
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 configuration allows for precise current detection without enlarging the module, reduces part count, and simplifies the structure, while improving temperature correction precision and maintaining insulation.
Implementation Method 1
a current sensor which is arranged to be at least partially overlapped with or at least partially surrounded by the first conductor in the plan view, and outputs a signal corresponding to a magnitude of a magnetic field generated by a measurement current flowing through the first conductor as a signal representing a current value of the measurement current
Data Source
AI summary
A power module may include; a first power semiconductor mounted on an insulating substrate; a first conductor at least partially overlapped with the first power semiconductor in a plan view, electrically coupled to a first terminal of the first power semiconductor, and extending along a surface of the insulating substrate in a first direction; a current sensor which is arranged to be at least partially overlapped with or at least partially surrounded by the first conductor in the plan view,; an encapsulating portion which encapsulates them, in a state in which the first conductor and the current sensor are insulated from each other; and a first external terminal electrically coupled to the first conductor and exposed from the encapsulating portion. The current sensor may be arranged between the first external terminal and the first power semiconductor in the first direction in the plan view.