Power Electronic Packaging for Transient Thermal Peak Management

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Solution Overview

Problem

Current thermal management solutions for power electronics primarily focus on steady-state operations, neglecting transient processes with time-varying loads, which can lead to reduced performance, reliability, and increased device weight and footprint.

Innovation Solution

A power electronic package design incorporating encapsulated heat sinks with a melting point between 80°C and 120°C, thermally conductive heat spreading elements like nano-sized graphene particles, and heat pipes with a working fluid boiling point in the same range, dispersed within an encapsulant to effectively manage heat dissipation during transient processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional steady-state cooling solutions are used, then thermal management is adequate for constant loads, but performance and reliability deteriorate during transient processes with time-varying loads

Engineering Contradiction:
ImprovereliabilityVSAvoidadaptability to transient loads
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the thermal management approach from steady-state constant thermal conductivity to transient-variable thermal conductivity by incorporating phase change materials that alter their thermal properties in response to temperature changes during transient loading conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions of encapsulated heat sink materials (melting point 80-120°C) and heat pipe working fluids (boiling point 80-120°C) to absorb and dissipate heat dynamically during transient processes, enabling the system to adapt to time-varying loads

Inventive Principle:
Principle #36Phase transitions

2Temperature

If larger heat sinks are used to manage transient heat loads, then thermal management improves, but device weight and footprint increase

Engineering Contradiction:
Improvethermal management capabilityVSAvoidheat sink weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The patent employs phase change materials with melting points of 80-120°C that absorb large amounts of heat during transient peaks through melting, and heat pipes with working fluids having boiling points of 80-120°C that rapidly transport heat away from the die, enabling compact heat sink design without sacrificing transient thermal management capability

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent creates a composite thermal management system combining encapsulated phase change heat sink materials, thermally conductive heat spreading elements, and heat pipes within an encapsulant, achieving superior transient thermal performance in a compact configuration

Inventive Principle:
Principle #40Composite materials

3Temperature

If larger heat sinks are used to manage transient heat loads, then thermal management improves, but device footprint increases

Engineering Contradiction:
Improvethermal management capabilityVSAvoidheat sink footprint
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The patent utilizes phase transitions of encapsulated heat sink materials (melting point 80-120°C) and heat pipe working fluids (boiling point 80-120°C) to absorb and dissipate heat dynamically during transient processes, enabling compact heat sink design without sacrificing transient thermal management capability

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent embeds multiple thermal management components (encapsulated heat sinks, heat pipes, thermally conductive elements) within the encapsulant surrounding the semiconductor die, creating a nested compact structure that maximizes thermal management effectiveness within minimal footprint

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution enhances thermal management by absorbing and dissipating heat efficiently during peak loads, reducing the size and weight of heat sinks, and providing significant overheat protection, thereby improving performance and reliability while minimizing device footprint.

Implementation Method 1

an increased temperature of the PE package semiconductor die(s) may cause the heat sink material of the encapsulated heat sinks to melt, thereby absorbing heat from the semiconductor die(s)

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

a plurality of heat pipes may be located in the encapsulant... the at least one heat pipe is configured to direct heat away from the active surface of the semiconductor die

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Implementation Method 3

each encapsulated heat sink of the plurality of encapsulated heat sinks may further include a plurality of thermally conductive heat spreading elements located within the encapsulation layer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4273921A1Power electronic devices and methods of packaging power electronic devices tailored for transient thermal management
Publication Date: 2023.11.08 RTX CORP
  • EP4273921A1 patent drawingFigure 1
  • EP4273921A1 patent drawingFigure 2A~2B
  • EP4273921A1 patent drawingFigure 3A~3B

AI summary

A power electronic package may comprise a substrate (110), a semiconductor die (102) bonded to a first surface of the substrate (110), and an encapsulant (130) deposited over the semiconductor die (102) and substrate (110). A plurality of encapsulated heat sinks (132) may be dispersed in the encapsulant (130) and/or a plurality of heating pipes may be located in the encapsulant (130) and over an active surface (106) of the semiconductor die (102).