Vapor Chamber Heat Spreaders With Multi-Level Wick Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vapor chamber heat spreaders face dry out problems and thermal runaway due to insufficient lateral liquid flow paths at high heat fluxes, where condensed liquid cannot efficiently return to the evaporator, leading to vapor formation and potential device damage.
Innovation Solution
The implementation of multi-level wick structures with condenser and evaporator posts and a mesh layer, creating engineered vapor and liquid flow paths, including vertical and lateral liquid flow paths, to ensure timely and efficient liquid supply to the evaporator, preventing dry out and thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a lateral liquid flow path is used in conventional vapor chambers, then the structure is simple, but the liquid supply speed is insufficient at high heat fluxes causing dry out problems
Solution Approach 1:
The wick structure is segmented into multiple levels with distinct functional zones: a first wick layer near the condenser for liquid collection, a second wick layer near the evaporator for liquid distribution, and intermediate wick layers forming vertical channels. This segmentation enables faster liquid transport by creating dedicated vertical flow paths that bypass the limitations of conventional lateral flow, directly resolving the contradiction between liquid supply speed and structural simplicity.
Solution Approach 2:
The invention transitions from a conventional two-dimensional lateral liquid flow path to a three-dimensional multi-level wick structure with vertical channels. By adding the vertical dimension through stacked wick layers and intermediate channels, the liquid can travel directly downward from the condenser to the evaporator, dramatically increasing supply speed without proportionally increasing structural complexity.
2Length of moving object
If the lateral liquid flow path is used, then the manufacturing is simple, but the liquid flow path length is too long causing delayed liquid replenishment
Solution Approach 1:
The wick structure is divided into multiple discrete layers (first wick layer, intermediate wick layers, second wick layer) that can be manufactured separately and then assembled. This segmentation allows each layer to be optimized for its specific function while simplifying the overall manufacturing process through modular construction, enabling the complex three-dimensional flow paths to be built from simpler two-dimensional components.
Solution Approach 2:
The intermediate wick layers are nested between the first and second wick layers, with each layer containing specific channel structures. The vertical channels are formed by the nested arrangement of these layers, creating a compact three-dimensional structure where liquid flow paths are embedded within the wick matrix. This nesting approach reduces the overall path length while maintaining manufacturability through layered assembly.
3Reliability
If conventional wick structures are used, then the device complexity is low, but dry out problems occur at high heat fluxes leading to thermal runaway
Solution Approach 1:
Different regions of the wick structure have specialized properties: the first wick layer near the condenser is optimized for liquid collection, the intermediate layers create vertical transport channels for rapid replenishment, and the second wick layer near the evaporator ensures uniform liquid distribution to hot spots. This local optimization of wick properties in different zones enhances reliability by ensuring adequate liquid supply throughout the high heat flux regions without requiring a complete redesign of the entire structure.
Solution Approach 2:
The multi-level wick structure is designed to proactively replenish liquid to the evaporator before dry out conditions can develop. The vertical channels in the intermediate wick layers create preferential flow paths that rapidly transport condensed liquid downward, anticipating the liquid demand in high heat flux regions. This preliminary action prevents thermal runaway by maintaining liquid availability ahead of potential dry out scenarios.
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 multi-level wick structures effectively alleviate dry out issues and prevent thermal runaway by providing a shorter liquid flow path and faster liquid supply to hot spots, ensuring continuous condensation and boiling, thus maintaining device safety and performance.
Implementation Method 1
The condenser condenses the vapor over an adjacent porous surface into a liquid state
Implementation Method 2
condensed liquid is then carried back to the evaporator by means of a porous wick structure attached to the inside walls of the vapor chamber with capillary action
Implementation Method 3
The mesh layer is a porous layer having high permeability
Implementation Method 4
the heat from a heat generating device at hotspots boils a coolant inside the vapor chamber
Data Source
AI summary
A vapor chamber heat spreader includes a condenser arranged at a top end of the vapor chamber heat spreader, an evaporator arranged at an opposite end to the condenser; and multi-level wick structures. The multi-level structures include a first planar wick arranged adjacent to the condenser, a second planar wick arranged adjacent to the evaporator, a plurality of condenser posts for supplying liquid condensed by the condenser, a plurality of evaporator posts for supply the liquid towards the evaporator, and a mesh layer. The mesh layer is arranged between the condenser posts and the evaporator posts and configured to separate the condenser posts from the evaporator posts. The mesh layer includes a plurality of vent holes. The mesh layer is a porous layer having high permeability.