Vapor Chamber Bubble Pump Layout to Prevent Cooling Dry-Out
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vapor chambers used for cooling power electronics modules face dry-out issues due to insufficient capillary force, leading to high wall temperatures and reduced component lifetime, especially when evaporation flow lengths exceed the capillary force's capability.
Innovation Solution
Incorporating a bubble pump channel within the vapor chamber that uses vapor bubbles to transport liquid cooling medium from a lower inlet to an upper outlet, preventing dry-out by ensuring adequate liquid supply to regions prone to liquid deficiency and hot spots, thereby enhancing cooling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the evaporation flow length is increased to cool larger heat sources, then the cooling coverage is improved, but the capillary force becomes insufficient leading to dry-out phenomenon
Solution Approach 1:
The baseplate is divided into multiple channels, each functioning as an independent bubble pump. This segmentation allows liquid to be transported through multiple parallel paths, ensuring reliable liquid supply across larger cooling areas while maintaining adequate liquid flow in each channel.
Solution Approach 2:
Vapor bubbles act as intermediaries to transport liquid from the liquid reservoir to the evaporation regions. The bubbles rise due to buoyancy and carry liquid along the channel walls, enabling liquid transport over extended distances beyond the capillary force range.
2Device complexity
If conventional vapor chamber design is used, then the structure is simple, but dry-out occurs leading to high wall temperatures and reduced component lifetime
Solution Approach 1:
The bubble pump channels are integrated directly into the baseplate structure, merging the liquid transport function with the heat transfer component. This combination maintains structural simplicity while preventing dry-out and extending component lifetime through improved liquid supply.
3Reliability
If bubble pump channels are added to ensure adequate liquid supply, then dry-out is prevented, but the device complexity increases
Solution Approach 1:
The bubble pump channels are integrated directly into the baseplate structure, merging the liquid transport function with the heat transfer component. This combination maintains structural simplicity while preventing dry-out and extending component lifetime through improved liquid supply.
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 bubble pump mechanism effectively increases the cooling performance of vapor chambers by ensuring consistent liquid distribution, reducing the risk of dry-out and maintaining lower temperatures, thereby extending the lifespan of electronic components.
Implementation Method 1
The bubbles also may lift the liquid cooling medium, since they have a lower density than the liquid cooling medium
Implementation Method 2
Inside the channel due to heating, vapor bubbles form
Implementation Method 3
vapor bubbles form, which expand and press liquid cooling medium in the channel towards the outlet
Implementation Method 4
the baseplate is adapted for transferring heat from the attachment side to the cavity, such that cooling medium evaporates at the evaporator side
Implementation Method 5
The cooling medium in vapor form then condenses at the condenser wall, which may be seen as a condenser side
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A vapor chamber (12) for cooling a heat source (14) comprises a cavity (16) between a baseplate (20) and a condenser wall (18), the cavity (16) containing a cooling medium (22); wherein the baseplate (20) has an evaporator side (26) towards the cavity (16) and an attachment side (28) opposite to the evaporator side (26) for attaching the heat source (14); wherein the baseplate (20) is adapted for transferring heat from the attachment side (28) to the cavity (16), such that cooling medium (22) evaporates at the evaporator side (26) and condenses at the condenser wall (18); and wherein the vapor chamber (12) further comprises a channel (40), which is at least partially connected to the baseplate (20), with an inlet (42) below a liquid level (38) of the cooling medium (22) and an outlet (44) above the liquid level (38) and which provides a bubble pump (46) for transporting the liquid medium (22) from the inlet (42) to the outlet (44).