Insulated Fluid-Cooled Power Module Without Ceramic Thermal Barrier

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Solution Overview

Problem

Existing IGBT power modules suffer from poor thermal conductivity in ceramic layers, leading to inadequate heat dissipation and reduced reliability due to high thermal resistance, which can damage chips and compromise module performance.

Innovation Solution

Employing a heat conducting layer with a thermal conductivity coefficient of 200 W/mK or higher, combined with a hollow housing filled with an insulated cooling medium, to facilitate rapid heat transfer and insulation, eliminating the need for a ceramic insulation layer and enhancing heat dissipation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a ceramic layer is used for insulation between chip and outside, then insulation reliability is improved, but thermal conductivity deteriorates

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidthermal conductivity
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent removes the ceramic insulation layer from the heat dissipation path. Instead of using ceramic for insulation, the invention uses a metal substrate with insulated coating that provides both thermal conduction and insulation functions, extracting the harmful thermal barrier function from the system while maintaining electrical insulation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs composite material structure consisting of metal substrate combined with insulated coating layers. This composite structure integrates the high thermal conductivity of metal with the insulation properties of the coating, resolving the contradiction between thermal conduction and insulation requirements.

Inventive Principle:
Principle #40Composite materials

2Reliability

If heat dissipation assembly is disposed outside ceramic layer, then insulation is maintained, but heat transfer efficiency deteriorates

Engineering Contradiction:
ImproveinsulationVSAvoidheat transfer efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts the ceramic insulation layer from the heat dissipation path and replaces it with a metal substrate structure. This removal eliminates the thermal barrier that prevented efficient heat transfer from chip to heat dissipation assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the insulation function with the metal substrate structure by applying insulated coatings directly on the metal surfaces. This combination allows the heat dissipation assembly to be in direct thermal contact with the chip while maintaining necessary insulation where required.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If ceramic layer and silicone ester layer are used for heat conduction path, then insulation is provided, but thermal resistance increases

Engineering Contradiction:
ImproveinsulationVSAvoidthermal resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent removes ceramic layers from the heat conduction path and replaces them with metal substrates having insulated coatings. This extraction eliminates the high thermal resistance associated with ceramic materials while maintaining insulation through the coating layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the material parameters of the heat conduction path by using metal substrates with high thermal conductivity instead of ceramic materials with low thermal conductivity. The insulated coating parameters are optimized to provide sufficient insulation while minimizing thermal resistance.

Inventive Principle:
Principle #35Parameter changes

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

The solution significantly reduces thermal resistance, improves heat dissipation performance, and increases reliability by ensuring timely heat transfer and insulation, allowing for deep integration with motor systems in electric vehicles.

Implementation Method 1

heat generated by the chip may be quickly transferred to the heat dissipation assembly through the heat conducting layer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the cooling medium may be an oil-cooled medium, and may share a cooling system with an oil-cooled motor

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 3

the cooling medium may further provide an insulated packaging environment for the chip to increase insulation between the chip and external environment components

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4322212B1Power module, inverter, and vehicle
Publication Date: 2026.03.25 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4322212B1 patent drawingFigure 1~2
  • EP4322212B1 patent drawingFigure 3
  • EP4322212B1 patent drawingFigure 4~6

AI summary

This application provides a power module, an inverter, and a vehicle. The power module includes a chip, a heat conducting layer, and a heat dissipation assembly. A thermal conductivity coefficient of the heat conducting layer is greater than or equal to 200 W/mK. The heat dissipation assembly includes a heat dissipation housing. The heat dissipation housing encloses accommodation space, and the chip and the heat conducting layer are disposed in the accommodation space. At least a part of the heat dissipation housing is a hollow housing, and at least one side of the chip is in contact with the hollow housing through the heat conducting layer. The hollow housing is filled with a cooling medium for cooling the heat conducting layer, and the cooling medium is an insulated fluid medium. According to the power module in this application, insulation and sealing of the chip is implemented through the heat dissipation housing and the cooling medium having an insulation property, and a ceramic layer does not need to be disposed as an insulation layer additionally, so that thermal resistance of the power module can be significantly reduced, and heat dissipation performance and reliability of the power module can be improved.