Modular Immersion Cooling for Power Circuit Boards

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Solution Overview

Problem

Modern power electronic control modules face challenges in cooling, particularly with solid state power controllers like MOSFETs, due to transient heat generation from load in-rush currents, flyback, and other faults, and existing fluid immersion cooling methods complicate board replacement and maintenance.

Innovation Solution

A cooling arrangement where individual power transistors or groups are enclosed with a dielectric cooling fluid and a pressure relief valve, allowing the enclosure to be removed and reinserted without releasing the fluid, enabling tailored cooling and easy replacement of circuit boards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the entire control module is surrounded by cooling fluid for immersion cooling, then heat dissipation efficiency is improved, but replacement and maintenance of individual circuit boards becomes difficult

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidreplacement of line removable modules
Core Design Contradiction:
TemperatureVSEase of repair

Solution Approach 1:

The control module is divided into separate functional units: individual circuit boards can be removed and replaced without affecting the cooling fluid containment. Each circuit board slot has its own shielding structure that can be independently accessed, allowing module replacement while the cooling fluid remains contained in the main housing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A hermetic seal acts as an intermediary barrier between the cooling fluid and the external environment. This seal allows individual circuit boards to be removed and replaced through designated access points without compromising the fluid containment, thus enabling maintenance while maintaining cooling efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a hermetic seal is used for fluid cooling circuits, then cooling fluid containment is improved, but repairability and ease of maintenance deteriorates

Engineering Contradiction:
Improvefluid containmentVSAvoidmaintenance of cooling circuit
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The hermetic seal system is segmented into multiple access points distributed around the housing. These access points allow targeted maintenance of specific cooling zones without requiring complete system disassembly, maintaining both fluid containment integrity and repairability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The housing is pre-designed with integrated access points and removable shielding structures that provide predetermined maintenance pathways. This preliminary design enables technicians to access and maintain cooling circuits without compromising the hermetic seal, as the access points are built into the containment structure itself.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If individual circuit boards are made removable for customization, then adaptability is improved, but cooling fluid containment becomes more complex

Engineering Contradiction:
Improvecustomization of control moduleVSAvoidcooling fluid containment structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The containment structure is segmented into modular sections corresponding to each circuit board slot. Each section has its own shielding and sealing elements that can be independently configured, allowing customized circuit board arrangements while maintaining simple fluid containment through standardized modular components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The housing and shielding structures are designed with universal, standardized features that serve multiple functions: they provide mechanical support for removable circuit boards, maintain hermetic sealing, and enable customized configurations. This multi-functionality reduces overall system complexity despite the adaptability requirements.

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

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 allows for efficient heat dissipation and facilitates the replacement or repair of individual line removable modules, enabling tailored cooling configurations and simplifying maintenance in complex control systems.

Implementation Method 1

fluid flowing adjacent to the power transistor is heated and flows away, towards the enclosure wall, where it may dissipate heat to the outer environment

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

fluid flowing adjacent to the power transistor is heated and flows away

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

Pressure relief valve allows fluid to then flow outward of the enclosure

Methodology Applied
Scientific EffectPressure relief: Depressurisation

Implementation Method 4

As the fluid absorbs this heat, the fluid expands such that the pressure within the chamber rises

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3193572B1Immersion cooling of power circuit
Publication Date: 2023.03.22 HAMILTON SUNDSTRAND CORP
  • EP3193572B1 patent drawingFigure 1
  • EP3193572B1 patent drawingFigure 2~3
  • EP3193572B1 patent drawingFigure 4

AI summary

A cooling arrangement has a circuit board (24) and a plurality of electronic components (32) in operable communication with the circuit board. An enclosure (30) is attached to the circuit board and configured to retain a fluid around at least one of the plurality of electronic components (32). The circuit board (24) with the enclosure (30) is attached thereto being removably connectable to a motherboard.