Field-Graded Power Converter Substrate for Thermal Integration

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Solution Overview

Problem

The compactness and power density of power converters are limited due to the need for mechanical fastening of components, which compromises thermal performance and ease of assembly, especially in highly-integrated designs where interface materials reduce interconnectivity between substrates.

Innovation Solution

A power converter is developed using a field graded substrate with blended conductor and insulator materials, integrated power device dies, and a heat sink formed through additive manufacturing, allowing for enhanced thermal and mechanical compatibility without the need for external interface materials, and featuring a polymer layer and conductors for electrical interconnections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If components are mechanically fastened together using connectors or thermal interface materials, then ease of assembly is improved, but thermal performance deteriorates and power density is limited

Engineering Contradiction:
Improveease of assemblyVSAvoidthermal performance
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent merges the substrate and heat sink into a single integrated component manufactured via additive manufacturing. The field graded substrate directly forms the heat dissipation structure without requiring separate thermal interface materials or mechanical fasteners, eliminating thermal resistance layers while maintaining ease of assembly through monolithic construction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs field graded materials where the substrate composition varies spatially: regions closer to power devices contain higher metal content for thermal conduction, while regions farther away contain more ceramic for electrical insulation. This composite structure optimizes both thermal performance and electrical isolation without requiring additional interface materials.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If interface material is used to interconnect substrates, then ease of assembly is improved, but thermal performance deteriorates and power density is limited

Engineering Contradiction:
Improveease of assemblyVSAvoidthermal performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent eliminates the need for separate interface materials by integrating the heat sink functionality directly into the substrate structure. The additive manufacturing process creates a continuous thermal pathway from power devices through the field graded substrate to the heat dissipation structures, removing thermal resistance introduced by interface materials.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The field graded substrate exhibits spatially varying material properties: areas adjacent to power devices have high thermal conductivity for efficient heat extraction, while peripheral areas have higher electrical insulation properties. This local optimization eliminates the need for additional interface materials while maintaining both thermal and electrical performance.

Inventive Principle:
Principle #3Local quality

3Temperature

If complex geometries are implemented to enhance cooling, then thermal performance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent utilizes additive manufacturing to create complex three-dimensional heat sink geometries including fins, channels, and variable thickness regions that would be difficult or impossible to achieve with traditional manufacturing. The build orientation and layer-by-layer construction enable optimized thermal pathways and cooling structures without proportionally increasing manufacturing complexity.

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

This approach enables a high power density power converter with improved thermal performance and reliability by reducing mechanical and electrical stress, eliminating the need for external interface materials, and allowing for complex geometries that enhance cooling efficiency.

Implementation Method 1

a graded layer that blends conductor and insulator material, the graded layer having an insulator core

Methodology Applied
Scientific EffectGraded layer blending: Composite Materials

Implementation Method 2

a heat sink that is integrally formed with the second conductor layer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the heat sink includes a base plate and a plurality of cooling fins

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

a polymer layer on the field graded substrate, and one or more conductors over the polymer layer

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 5

Power converters are typically assembled together from a variety of components with a mixture of custom and off-the-shelf parts

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Data Source

PatentEP4284123A1Power converter
Publication Date: 2023.11.29 HAMILTON SUNDSTRAND CORP
  • EP4284123A1 patent drawingFigure 1
  • EP4284123A1 patent drawingFigure 2~3
  • EP4284123A1 patent drawingFigure 4

AI summary

A power converter includes a field graded substrate (102), a plurality of power device dies (104) attached to the field graded substrate (102), a polymer layer on the field graded substrate (102), one or more conductors over the polymer layer, and a plurality of power conditioning components mounted on the field graded substrate (102) to form a power converter circuit. The field graded substrate (102) includes a first conductor layer (208), a graded layer that blends conductor and insulator material, and a second conductor layer (212), the graded layer having an insulator core.