Electrodeposited Capillary Heat Sink Structure for High Heat Flux
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sintered capillary structures in heat sinks have insufficient capillary driving force and high liquid resistance, leading to low boiling heat transfer coefficients at high heat flux densities, resulting in excessive temperature differences and potential dry burning issues.
Innovation Solution
A thermally conductive structure with a capillary structure formed via electrochemical deposition, featuring media pores of varying sizes that extend through the structure, enhancing capillary force and boiling heat transfer by allowing quick bubble escape and medium circulation, thereby reducing temperature differences and improving heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sintered capillary structure is used, then the heat sink can provide basic heat dissipation, but the capillary driving force is insufficient and liquid resistance is high, leading to low boiling heat transfer coefficients at high heat flux densities
Solution Approach 1:
The patent uses a porous copper foam material as the capillary structure, which provides high porosity (70-90%) and large specific surface area. The porous structure offers numerous capillary channels with small diameters that generate strong capillary driving forces, enabling efficient liquid return even at high heat flux densities where conventional sintered structures fail.
Solution Approach 2:
The patent creates a composite structure by combining the porous copper foam capillary wick with a VC (vapour chamber) heat sink. This composite design integrates the high capillary action of the foam structure with the heat spreading capability of the VC, achieving both reliable liquid transport and effective heat dissipation.
2Speed
If the capillary driving force is increased to improve liquid flowback, then the liquid resistance may increase, resulting in higher temperature differences
Solution Approach 1:
The patent applies different pore size distributions in different regions of the capillary structure. The region closer to the heating surface has smaller pores for stronger capillary action and faster liquid return, while other regions have larger pores to reduce liquid flow resistance. This local differentiation optimizes both flowback speed and temperature uniformity.
Solution Approach 2:
The patent transitions from traditional two-dimensional sintered structures to a three-dimensional porous foam structure. The 3D network of interconnected pores provides multiple parallel flow paths, dramatically increasing the effective capillary driving force while maintaining low liquid resistance through the volumetric distribution of channels.
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
The proposed structure effectively enhances boiling heat transfer coefficients and liquid flowback speed, reducing temperature differences and preventing dry burning, thus improving heat dissipation efficiency at high heat flux densities.
Implementation Method 1
a first capillary structure formed by using an electrochemical deposition process
Implementation Method 2
a working medium boils in a process of continuously absorbing heat transferred by the thermally conductive plate, and bubbles generated when the working medium is boiling
Implementation Method 3
a working medium boils in a process of continuously absorbing heat
Implementation Method 4
A capillary wick inside the VC heat sink is used as a channel for transporting the working medium of water, and has functions of heat transfer and mass transfer, provides a liquid flowback driving force
Data Source
AI summary
A thermally conductive structure is provided. The thermally conductive structure includes a thermally conductive plate and a first capillary structure formed by using an electrochemical deposition process. The first capillary structure is disposed on a side that is of the thermally conductive plate and that is opposite to a heat source. The first capillary structure has a plurality of media pores with different pore sizes, the plurality of media pores all extend along a thickness direction of the first capillary structure, and the plurality of media pores all run through the first capillary structure. The thermally conductive structure in this application can prevent untimely liquid flowback and resolve a problem of an excessively high temperature difference at a high heat flux density, thereby improving applicability and heat dissipation effect of the thermally conductive structure.