Power Module Vapor Chamber Assembly for Low-Resistance Cooling

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Solution Overview

Problem

Existing power electronic modules face challenges in effectively dissipating heat due to limitations at the transition between the power module and the heat sink, particularly at solid-state interfaces, which are prone to thermal resistance and instability.

Innovation Solution

The integration of a first vapor chamber device between the power module and heat sink, combined with a second vapor chamber device on a side of the power chip, enhances heat dissipation by utilizing side surfaces and optimizing the heat flow path, eliminating solid-state interfaces and improving thermal conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If large-area solder or sintered connections and thermal pastes are used to connect the power module to the heat sink, then the thermal contact resistance is reduced, but the manufacturing complexity and process demands increase significantly

Engineering Contradiction:
Improvethermal contact resistanceVSAvoidmanufacturing process demands
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent merges the mechanical support function, electrical insulation function, and heat transfer function into a single integrated substrate structure. This eliminates the need for separate thermal pastes, gap pads, or solder connections between the power module and heat sink, as the substrate itself provides all these functions simultaneously, thereby reducing manufacturing complexity while maintaining low thermal contact resistance

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The substrate is designed to perform multiple functions simultaneously: it provides mechanical support for the power chip, electrical insulation between different potential regions, and efficient heat transfer to the heat sink. This multi-functionality eliminates the need for multiple separate components and connection methods, simplifying the manufacturing process while achieving excellent thermal contact

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

2Temperature

If the heat sink interface area is made of materials with excellent thermal conductivity, then the heat dissipation performance is improved, but the device complexity and material requirements increase

Engineering Contradiction:
Improveheat dissipation performanceVSAvoidmaterial requirements
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The substrate integrates the heat transfer function directly into its base structure rather than requiring a separate high-conductivity heat sink interface layer. The substrate material itself is designed with sufficient thermal conductivity to efficiently transfer heat from the power chip to the heat sink, eliminating the need for additional specialized materials and reducing device complexity

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If non-overlapping surface vapor chamber devices are integrated into the heat sink, then the lateral heat spreading is improved, but the device complexity increases

Engineering Contradiction:
Improvelateral heat spreadingVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent transitions from lateral heat spreading within the heat sink to vertical heat spreading through the substrate structure. The substrate is designed with optimized thickness and thermal conductivity to spread heat laterally as it conducts vertically from the power chip to the heat sink, achieving effective heat distribution without adding complex vapor chamber devices to the heat sink

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If the power module is miniaturized as a surface-mount device, then the productivity and integration are improved, but the heat dissipation capability deteriorates

Engineering Contradiction:
Improveintegration efficiencyVSAvoidheat dissipation capability
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent optimizes the substrate thickness parameter to achieve the right balance between miniaturization and heat dissipation. By carefully selecting and controlling the substrate thickness, the design enables effective heat transfer from the small power chip to the heat sink while maintaining the compact surface-mount form factor, thus improving both integration efficiency and heat dissipation capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The substrate is designed as a composite structure with optimized material properties to achieve high thermal conductivity in the heat transfer direction while maintaining mechanical strength and electrical insulation. This composite approach enables the miniaturized power module to dissipate heat effectively despite its small size

Inventive Principle:
Principle #40Composite materials

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 approach achieves efficient heat dissipation through multiple paths, reducing thermal resistance and enhancing cooling performance, particularly in miniaturized surface-mount devices, while simplifying system integration and ensuring electrical insulation.

Implementation Method 1

a first vapor chamber device (20) is formed between the power module and the heat sink... optimized heat flow by eliminating contact-related thermal resistances

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

vapor chamber device... efficient heat transfer toward the heat sink

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Implementation Method 3

a heat absorption side of the second vapor chamber device (26), wherein a heat dissipation side of the second vapor chamber device (26) is arranged at the joining zone (18)

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Data Source

PatentEP4579733A1Assembly for an electronic computing device with at least one power module, a heat sink for cooling the power module and assembly composite
Publication Date: 2025.07.02 SIEMENS AG
  • EP4579733A1 patent drawingFigure 1
  • EP4579733A1 patent drawingFigure 2
  • EP4579733A1 patent drawingFigure 3

AI summary

The invention relates to an arrangement (10) with at least one power module (12) and a heat sink (14) for cooling the power module (12), wherein the power module (12) is formed with at least one power chip (16) and with a joining zone (18) on which the power chip (12) is arranged, wherein a first steam chamber device (20) is formed between the power module (12) and the heat sink (14), wherein at least one side (22) of the first steam chamber device (20) is delimited by the power module (12) and at least one further side (24) of the first steam chamber device (20) is delimited by the heat sink (14), and wherein the power module (12) has at least one second steam chamber device (26) which is arranged on a yet further side (28) of the power chip (16), which is not the underside, with a heat absorption side of the second steam chamber device (26),wherein a heat dissipation side of the second steam chamber device (26) is arranged at the joining zone (18). Furthermore, the invention relates to an assembly composite (50).