Heat Pipe Window Structure for Low-Resistance Cold Plate Cooling
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Solution Overview
Problem
Conventional heat pipe designs for computing systems have limited surface area for heat transfer and thermal resistance, leading to reduced thermal performance and increased risk of dryout, which can negatively impact semiconductor devices.
Innovation Solution
The introduction of a heat pipe assembly with a cavity or window on the inner surface of the heat pipe and/or cold plate, increasing the thermal transfer area and capillary limit without requiring large amounts of working fluid, and using pure copper for improved conductivity, along with a flipped pedestal arrangement to reduce thermal resistance and enhance structural stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional heat pipe designs are used with traditional soldering on cold plate, then the structure is simple and manufacturing is easy, but the surface area for heat transfer is limited and thermal resistance is high
Solution Approach 1:
The patent introduces a cavity or window feature on the inner surface of the heat pipe, transforming a two-dimensional surface into a three-dimensional structure. This dimensional change increases the heat transfer surface area without proportionally increasing the overall device volume, allowing more heat transfer area within the same footprint.
Solution Approach 2:
The heat pipe assembly is divided into multiple functional components: the heat pipe body, the cavity/window structure, the cold plate, and the pedestal. This segmentation allows each component to be optimized independently for its specific function while assembling to create the overall thermal management system with improved performance.
2Reliability
If more heat pipes are added or multi-directional heat pipes are used to increase heat transfer capability, then thermal performance improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
Instead of uniformly increasing heat transfer capability across the entire system by adding multiple heat pipes, the patent applies local quality enhancement by creating a cavity or window specifically at the cold plate interface where heat transfer is most critical. This localized modification concentrates thermal performance improvement where it is most needed without requiring multiple additional heat pipes.
Solution Approach 2:
The cavity or window structure is nested within the heat pipe body, creating a compact design where the heat transfer enhancement feature is contained within the existing heat pipe volume. This nesting approach allows increased heat transfer area without proportionally increasing the overall device size or requiring additional separate components.
3Reliability
If traditional heat pipe designs are used, then manufacturing is straightforward, but the risk of dryout is high which reduces reliability
Solution Approach 1:
The cavity or window structure creates increased surface area with potential porous characteristics that enhance capillary action. This porous-like structure increases the capillary limit and working fluid storage capacity, reducing the risk of dryout by ensuring adequate fluid supply to the evaporation surface during operation.
Solution Approach 2:
The cavity or window is pre-formed during heat pipe manufacturing to increase working fluid storage capacity before the heat pipe is assembled and deployed. This preliminary action ensures that sufficient working fluid is available from the start, preventing dryout conditions before they can occur during operation.
4Temperature
If pure copper is used to improve conductivity, then thermal performance improves, but material cost and weight increase
Solution Approach 1:
The patent changes the material parameter from conventional materials to pure copper specifically at the cold plate interface where thermal conductivity is most critical. This parameter change optimizes thermal performance at the most important heat transfer location without requiring pure copper throughout the entire heat pipe assembly, thus limiting the weight increase to only the essential components.
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 design enhances thermal performance by reducing thermal resistance and the risk of dryout, improving the cooling efficiency of semiconductor devices and extending the lifespan of the heat pipe assembly.
Implementation Method 1
Heat pipes are a heat-transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces
Implementation Method 2
The working fluid within the heat pipe evaporates at the hot interface and condenses at the cold interface, facilitating efficient heat transfer
Implementation Method 3
The working fluid within the heat pipe evaporates at the hot interface and condenses at the cold interface, facilitating efficient heat transfer
Implementation Method 4
A capillary wick structure is provided within the heat pipe to draw the working fluid from the condensation zone back to the evaporation zone
Implementation Method 5
using pure copper for improved conductivity
Data Source
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AI summary
Disclosed embodiments are relate to heat transfer devices or heat exchangers for computing systems, and in particular, to heat pipes for improved thermal performance at a cold plate interface. A thermal exchange assembly includes a heat pipe (HP) directly coupled to a cold plate. The HP includes a window, which is a recessed or depressed portion of the HP. The window is attached to the cold plate at a window section of the cold plate. The cold plate is configured to be placed on a semiconductor device that generates heat during operation. The cold plate transfers the heat to the HP with less thermal resistance than existing HP solutions. Other embodiments may be described and/or claimed.