Thermal Interface Device for Heat Pipe Amplifier Cooling

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Solution Overview

Problem

High power amplifiers, such as RF and microwave amplifiers, face inefficiencies in heat dissipation due to bulky heat sink components and limited direct connection capabilities with heat pipe and water flow-based heat sinks, which hinder efficient thermal transfer and require additional bulk metal for mounting flanges and may compromise electrical ground contact.

Innovation Solution

A thermal interface device is used to indirectly couple high power transistors to heat pipe or circulating fluid heat sinks, creating multiple thermal junctions to facilitate efficient heat transfer while minimizing mass and size, utilizing materials with high thermal conductivity and electrical grounding capabilities, such as copper, silver, and aluminum, to enhance heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a heat sink with large volume of metal and fins is used to dissipate heat, then heat dissipation capability is improved, but device volume and weight increase significantly

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoiddevice volume
Core Design Contradiction:
Loss of energyVSVolume of moving object

Solution Approach 1:

The patent changes the material parameters by using heat pipe technology with phase change materials (liquid/vapor transitions) instead of traditional solid metal heat sinks. This allows achieving the same heat dissipation capability with significantly reduced volume and weight, as the heat pipe efficiently transports heat through phase change rather than relying on large thermal mass.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions of the heat pipe working fluid (liquid to vapor and back) to transport heat from the heat source. The latent heat of vaporization and condensation enables highly efficient heat transfer with compact dimensions, resolving the contradiction between heat dissipation capability and device volume.

Inventive Principle:
Principle #36Phase transitions

2Loss of energy

If heat pipe technology is used to improve heat dissipation efficiency, then heat transfer efficiency is improved, but the ability to provide direct mechanical connection and electrical ground contact is worsened

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidmechanical connection capability
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The patent introduces an intermediary thermal interface device that couples the transistor to the heat pipe heat sink. This intermediary component provides the necessary mechanical connection and electrical ground contact while maintaining efficient thermal transfer to the heat pipe, thus resolving the contradiction between heat transfer efficiency and mechanical connection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the thermal management system into distinct functional components: the heat pipe heat sink for efficient heat transfer, and a separate thermal interface device for mechanical connection and electrical grounding. This segmentation allows each component to optimize its specific function without compromise.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If multiple thermal junctions are introduced to accommodate heat pipe connection, then mechanical connection is improved, but thermal resistance increases

Engineering Contradiction:
Improvemechanical connectionVSAvoidthermal resistance
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent minimizes thermal resistance at each junction by optimizing the material parameters and contact surfaces of the thermal interface device. Using high thermal conductivity materials and ensuring optimal contact pressure and surface finish reduces the cumulative thermal resistance of multiple junctions, maintaining efficient heat transfer while enabling proper mechanical connection.

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 reduces the weight and size of amplifier devices, improves thermal dissipation efficiency, and maintains electrical performance by allowing precise heat extraction and minimizing thermal resistance through multiple thermal paths, thereby enhancing the overall efficiency of heat transfer from transistors to heat sinks.

Implementation Method 1

A thermal interface device is used to indirectly couple high power transistors to heat pipe or circulating fluid heat sinks, creating multiple thermal junctions to facilitate efficient heat transfer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

heat pipe technology which is highly efficient at removing heat using conduction and convection, or circulating fluid heat pipe technology. The heat pipes are located close to the surface of the heat sink which contacts the hot surface

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

Examples of heat pipe heat sinks may also use the latent heat of a fluid (for example, ethanol, acetone, water, sodium or mercury)

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Implementation Method 4

A heat sink, such as a finned heat sink, may be provided in order to transfer heat to the surrounding atmosphere

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2603928B1Apparatus and method for thermal interfacing
Publication Date: 2020.03.18 EMBLATION
  • EP2603928B1 patent drawingFigure 1(a)~2(b)
  • EP2603928B1 patent drawingFigure 3(a)~3(b)
  • EP2603928B1 patent drawingFigure 4(a)~4(b)

AI summary

An apparatus (20) for use as an amplifier has a transistor (26) for providing signal amplification, a heat pipe or circulated fluid heat sink (22) and a thermal interface device (24) for providing mechanical and thermal connection between the transistor (26) and the heat sink (22). In use, to facilitate efficient transfer of heat/thermal energy from the transistor (26) to the heat sink (22), the plate (24) is provided between the heat sink (22) and the transistor (26). The plate (24) connects the heat sink (22) to the transistor (26) and provides a thermal conduit therebetween.