Looped Capillary Heat Pipe Layout for Thin Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The performance of heat pipes with wicks deteriorates as the thickness of the wick decreases, limiting the implementation of ultra-compact cooling systems.

Innovation Solution

A heat pipe design featuring a capillary structure with patterned portions of varying diameters and bends, including a first capillary portion with a larger diameter and a second portion with a smaller diameter, connected by turn portions, optimized for uniform distribution and circulation of the working fluid, even in larger areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a wick structure with predetermined thickness is used to circulate working fluid, then the heat pipe can function, but the performance deteriorates as the thickness decreases, limiting ultra-compact cooling systems

Engineering Contradiction:
Improveheat pipe thicknessVSAvoidheat dissipation performance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The invention removes the wick structure from the heat pipe system entirely. Instead of using a wick to circulate the working fluid, the patent employs a capillary channel with specific geometric features (bends and diameter variations) that enable fluid circulation through capillary action and pressure differentials alone, thus eliminating the space-consuming wick component

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical parameters of the capillary channel, specifically introducing bends and diameter variations along the channel length. These parameter changes create pressure differentials and enhance capillary effects, enabling effective working fluid circulation without requiring a thick wick structure

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the capillary channel has uniform diameter and straight configuration, then the structure is simple, but the working fluid distribution becomes non-uniform in larger areas

Engineering Contradiction:
Improvecapillary structure complexityVSAvoidworking fluid distribution uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The invention applies local quality by creating non-uniform features within the capillary channel. Specifically, the channel includes sections with different diameters and strategic bends at specific locations. These localized variations in geometry create appropriate pressure differentials and flow resistance distribution, ensuring uniform working fluid circulation across the entire heat pipe area

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention introduces curvature elements (bends) into the otherwise straight capillary channel. These bends create centrifugal effects and pressure differentials that enhance fluid circulation and distribution uniformity, particularly in larger heat pipe areas where straight channels would result in poor fluid distribution

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

Enhances heat dissipation performance by ensuring uniform distribution and circulation of the working fluid, preventing liquid slug retention and improving heat dissipation efficiency in larger areas.

Implementation Method 1

pulsating heat pipes have been developed. These pipes induce capillary action without using a wick, allowing the working fluid to evaporate, condense, vibrate, and circulate effectively

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

allowing the working fluid to evaporate, condense, vibrate, and circulate effectively

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP4671659A1Heat pipe and electronic device including the heat pipe
Publication Date: 2025.12.31 SAMSUNG DISPLAY CO LTD
  • EP4671659A1 patent drawingFigure 1
  • EP4671659A1 patent drawingFigure 2
  • EP4671659A1 patent drawingFigure 3

AI summary

A heat pipe includes: a base plate; a capillary on the base plate and including a plurality of patterned portions connected to each other to form a closed loop; and a cover plate on one surface of the base plate and covering the capillary. Each of the plurality of patterned portions includes: a first capillary portion having a first diameter; a second capillary portion having a second diameter smaller than the first diameter; and a turn portion connecting the first capillary portion and the second capillary portion. The number of the turn portions per unit area is the greatest at a central portion of the base plate.