Flexible Thermally Conductive Sheet for Circuit Board Cooling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional thermal management solutions, such as cold plates and air cooling, are suboptimal and costly for low power components due to the need for precise positioning and excessive cooling power, while existing solutions fail to provide efficient and cost-effective cooling for both high and low power components in computer systems.

Innovation Solution

A mechanically flexible thermally conductive sheet is used to make thermal contact with both high and low power components, allowing a single fluid-cooled structure to efficiently cool all components by matching the topology of the circuit board and reducing the thickness of thermal interface materials needed for low power components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cold plate is used to cool low power components, then cooling efficiency is improved, but cost increases due to positioning and fluid connection requirements

Engineering Contradiction:

Improvecooling efficiencyVSAvoidcost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a flexible thermally conductive sheet that can conform to the circuit board topology and make thermal contact with multiple components of varying power levels. This flexible sheet eliminates the need for rigid cold plates and complex fluid connections for each component, thereby maintaining cooling efficiency while reducing manufacturing cost and complexity

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible thermally conductive sheet serves multiple functions: it acts as a thermal interface material for low power components, extends from the cold plate to reach additional components, and provides thermal contact across varying topographies. This single universal component replaces multiple specialized cooling solutions, reducing overall system cost while maintaining effectiveness

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a rigid cold plate is used, then thermal contact to high power components is effective, but adaptability to circuit board topology is reduced

Engineering Contradiction:

Improvethermal contact effectivenessVSAvoidadaptability to topology

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces rigid cold plates with flexible thermally conductive sheets that can bend and conform to the specific topology of the circuit board. This flexibility allows the sheet to adapt to varying component positions and heights while maintaining effective thermal contact, thus resolving the contradiction between thermal effectiveness and topological adaptability

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If thick thermal interface material is used for low power components, then thermal contact is achieved, but thermal resistance increases

Engineering Contradiction:

Improvethermal contactVSAvoidthermal resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The flexible thermally conductive sheet can deform to conform to component surfaces, achieving reliable thermal contact with minimal material thickness. This eliminates the need for thick thermal interface materials that would increase thermal resistance, as the flexibility of the sheet allows it to bridge minor surface irregularities without requiring excessive thickness

Inventive Principle:

Principle #30Flexible shells and thin films

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 provides cost-effective cooling for both high and low power components, enhances reworkability of the fluid-cooled circuit board assembly, and allows for unitary installation and removal of the cooling structure, optimizing thermal management while minimizing costs.

Implementation Method 1

A thermally conductive sheet is preformed to match the topology. The sheet has a first portion that makes thermal contact with the cold plate and a second portion that overlays the low power component or components. Thermal contact to the low power components is made through a second TIM or set of TIMs.

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11497143B2Mechanically flexible cold plates for low power components

Publication Date: 2022.11.08 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

An assembled circuit board has a topology that defines positions, dimensions and power dissipation of components mounted to the circuit board, including a high power component and one or more low power components. A cold plate makes thermal contact to the high power component through a thermal interface material. A thermally conductive sheet overlays the circuit board and is formed to match the topology of the low power component or components. The sheet has a first portion that makes thermal contact with the cold plate and a second portion that overlays the low power component or components. The cold plate removes heat directly from the high power component and indirectly through the thermally conductive sheet from the low power component or components. The thermally conductive sheet conforms to the topology of the low power components either by preforming or by flexibility.