Two-Phase Heat Conduction Layout for Compact Power Electronics Cooling

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Solution Overview

Problem

Current cooling methods for electronic components, particularly power electronics, are complex, costly, and inefficient due to the use of expensive materials and structural challenges, making it difficult to implement effective heat dissipation, especially in confined spaces and requiring high thermal conductivity materials like copper.

Innovation Solution

A two-phase cooling system with a continuous hydraulic connection between heat absorption, transport, and emission sections using a refrigerant that changes phases from liquid to gas, allowing efficient heat dissipation without pumps or moving parts, utilizing surface area-enhancing agents and materials like copper or aluminum for heat sinks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If expensive thermally conductive ceramics such as aluminum nitride are used as insulating layers, then heat dissipation performance is improved, but manufacturing costs and device complexity increase significantly

Engineering Contradiction:
Improveheat dissipation performanceVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The invention changes the thermal conductivity parameter of the housing material from conventional low values to at least 20 W/(m·K), preferably at least 50 W/(m·K). This is achieved by using metal matrix composite materials or sintered materials with specific compositional parameters (e.g., aluminum with ceramic particles, silicon carbide with binder phases), thereby improving heat dissipation without requiring complex ceramic insulating layers

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The housing serves multiple functions simultaneously: it provides structural support, electrical insulation, and thermal conduction. By making the housing itself thermally conductive (≥20 W/(m·K)), it eliminates the need for separate ceramic insulating layers with thermal management functions, reducing device complexity while maintaining heat dissipation performance

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

2Temperature

If large quantities of expensive metals such as copper are used, then thermal conductivity is improved, but manufacturing costs and technical complexity increase

Engineering Contradiction:
Improvethermal conductivityVSAvoidease of manufacture
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The invention uses composite materials (metal matrix composites or sintered materials) that combine metal binders with ceramic particles or crystalline phases to achieve high thermal conductivity (≥20 W/(m·K)) without requiring pure copper or aluminum. Examples include aluminum-based composites with silicon carbide, aluminum oxide, or graphite particles, which provide comparable thermal performance at lower cost and with improved manufacturability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention replaces expensive pure copper heat sinks and thermal conduction components with more economical metal matrix composite or sintered materials that achieve sufficient thermal conductivity (≥20 W/(m·K)) for the application, reducing material costs while maintaining adequate heat dissipation performance

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Temperature

If complex heat sinks and heat spreader plates are incorporated, then heat dissipation efficiency is improved, but component size and manufacturing complexity increase

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The invention merges the functions of the housing, heat spreader, and heat sink into a single integrated thermally conductive housing structure. The housing itself serves as the thermal management component, eliminating the need for separate heat spreader plates and complex heat sink assemblies, thereby reducing device complexity while maintaining heat dissipation efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing performs multiple functions: structural support, electrical insulation, and thermal conduction/dissipation. By integrating thermal management functions into the housing, the invention eliminates the need for separate heat spreader and heat sink components, reducing overall device complexity and component count

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

4Ease of manufacture

If air cooling methods are used, then manufacturing simplicity is maintained, but heat dissipation performance becomes insufficient for high heat flows

Engineering Contradiction:
Improveease of manufactureVSAvoidheat dissipation performance
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The invention changes the thermal conduction parameter of the housing material to at least 20 W/(m·K) (preferably ≥50 W/(m·K)), enabling the housing itself to function as an effective heat spreader that works in conjunction with air cooling, thereby achieving high heat dissipation performance without complicating the cooling system architecture

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 system achieves high heat dissipation per unit volume, reduces material and space requirements, and allows for flexible, compact designs with reduced maintenance, enabling efficient cooling of multiple components and reducing CO2 footprint.

Implementation Method 1

The heat conduction system is set up for operation of a two-phase cooling system by providing a continuous hydraulic connection between the at least one heat emission section, the at least one heat transport section and the at least one heat absorption section

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

a two-phase cooling system with a continuous hydraulic connection between heat absorption, transport, and emission sections using a refrigerant that changes phases from liquid to gas

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

at least one heat transport section between the heat absorption section and the heat emission section

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 4

at least one heat emission section, which has at least one surface area-enlarging means

Methodology Applied
Scientific EffectHeat sink: Heat Sink

Data Source

PatentEP4697876A1Heat conducting system
Publication Date: 2026.02.18 SIEMENS AG
  • EP4697876A1 patent drawingFigure 1
  • EP4697876A1 patent drawingFigure 2
  • EP4697876A1 patent drawingFigure 3

AI summary

The invention relates to a thermal conduction system for dissipating heat from electrically dissipated components. Furthermore, the invention relates to a power semiconductor unit and a power converter with such a thermal conduction system. The thermal conduction system comprises a heat absorption section (12), which is provided for a thermally conductive connection to an electrical component (2) to be cooled, a heat dissipation section (14), which has surface-enhancing means, and a heat transfer section (13) between the heat absorption section (12) and the heat dissipation section (14). The thermal conduction system (1) is configured for operation with two-phase cooling.