PWB Stiffener Tray Architecture for Conductive Module Cooling

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Solution Overview

Problem

Existing thermal management systems for electronic modules struggle to efficiently dissipate heat while maintaining structural support, particularly in applications where high heat dissipation is required.

Innovation Solution

A conductive thermal management architecture that employs a stiffener with tray sections on a printed wiring board (PWB) assembly, utilizing thermal pads for reduced thermal interface resistance and wedge lock mounting rails as heat sinks, secured with screws and adhesive film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a stiffener is used to provide mechanical support to the PWB, then structural support is improved, but weight increases

Engineering Contradiction:
Improvestructural supportVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The stiffener is constructed from aluminum alloy, a composite material that provides high strength-to-weight ratio. This allows the stiffener to deliver necessary structural support while minimizing weight addition compared to traditional materials like steel or solid aluminum blocks.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The stiffener is divided into a frame structure with multiple tray sections rather than a solid continuous structure. This segmentation reduces material usage and weight while maintaining structural support through the distributed frame geometry that provides rigidity where needed.

Inventive Principle:
Principle #1Segmentation

2Temperature

If traditional thermal management systems are used, then heat dissipation is achieved, but thermal interface resistance is high

Engineering Contradiction:
Improveheat dissipationVSAvoidthermal interface resistance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

Thermal pads are introduced as intermediary elements between the electronic modules and the stiffener tray sections. These thermal pads provide a compliant interface that fills gaps and conforms to surface irregularities, significantly reducing thermal interface resistance and improving heat transfer efficiency from the modules to the heat sink structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The thermal pads change the thermal contact parameters by providing a softer, more compliant material interface. This changes the contact pressure distribution and thermal conductivity at the interface, optimizing heat transfer while accommodating manufacturing tolerances and assembly variations.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the stiffener edges are used as heat sinks, then heat dissipation is improved, but structural complexity increases

Engineering Contradiction:
Improveheat dissipationVSAvoidstructural complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The stiffener is designed to perform multiple functions simultaneously: it provides mechanical structural support to the PWB, serves as a heat sink through its edges for thermal management, and incorporates tray sections for module mounting. This multi-functionality eliminates the need for separate heat sink components, reducing overall system complexity despite the enhanced thermal capabilities.

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

Solution Approach 2:

The structural support function and thermal management function are merged into a single integrated stiffener component. The same aluminum alloy frame that provides mechanical rigidity also serves as the heat dissipation pathway, eliminating the need for separate heat sink structures and reducing assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Strength

If wedge locks are used to secure the stiffener, then structural integrity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The wedge locks are pre-installed onto the mounting rails during the stiffener fabrication process rather than being installed separately during final assembly. This preliminary action ensures proper positioning and alignment, simplifies the final assembly process, and maintains structural integrity while reducing assembly complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The wedge lock mechanism is designed to be self-aligning and self-securing on the mounting rails. The wedge geometry automatically positions itself correctly during installation and provides inherent locking action, eliminating the need for complex adjustment procedures or additional fastening steps, thus maintaining ease of manufacture.

Inventive Principle:
Principle #25Self-service

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 effectively enhances heat dissipation by minimizing thermal interface resistance and utilizing the stiffener's edges as heat sinks, while maintaining structural integrity and scalability for various electronic module configurations.

Implementation Method 1

utilizing the stiffener's edges as heat sinks

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

wedge lock mounting rails as heat sinks

Methodology Applied
Scientific EffectHeat sink: Heat Sink

Implementation Method 3

adhesive film adheres the stiffener to the PWB

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3882963B1Conductive thermal management architecture employing a stiffener of a printed wiring board assembly
Publication Date: 2025.04.23 HAMILTON SUNDSTRAND CORP
  • EP3882963B1 patent drawingFigure 1
  • EP3882963B1 patent drawingFigure 2A~2B
  • EP3882963B1 patent drawingFigure 3

AI summary

An electronic assembly includes a printed wiring board (PWB) (160), and a stiffener (130) secured to the PWB (160). The stiffener (130) includes one or more tray sections (135). One or more electronic modules (110) is secured respectively to the one or more tray sections (135) of the stiffener (130).