Gradient Density Heat Sink for Thermal Resistance Reduction
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Solution Overview
Problem
Conventional heat sink designs fail to effectively manage thermal resistance between integrated circuits and forced air streams, limiting their cooling efficiency, and lack complex structures that could enhance performance.
Innovation Solution
A heat sink design featuring a cooling structure with decreasing material density from the heat generating device and perpendicular to the body part, utilizing a mesh or lattice structure that increases air and liquid flow passages with distance, formed through selective laser melting (SLM) additive manufacturing, allowing for monolithic connection and use of materials like Aluminum, Copper, or technical ceramics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional heat sink designs with uniform structure are used, then manufacturing is simpler, but thermal resistance is higher and cooling efficiency is limited
Solution Approach 1:
The heat sink employs a gradient structure where the material density varies spatially - higher density near the heat source for effective heat absorption, and lower density toward the outer regions for enhanced airflow. This local variation in structural properties optimizes both thermal management and fluid dynamics performance
Solution Approach 2:
The patent implements continuous parameter changes in the structure density throughout the heat sink volume. The density transitions from a first value at the heat source interface to a second value at the outer regions, creating an optimized gradient that simultaneously addresses thermal conduction and convective heat transfer requirements
2Productivity
If complex three-dimensional structures are introduced to improve cooling performance, then heat dissipation capability increases, but manufacturing difficulty and cost increase
Solution Approach 1:
The gradient structure density is achieved through controlled parameter changes during the additive manufacturing process, allowing complex geometries to be fabricated as monolithic structures. The varying density distribution is directly encoded in the 3D printing parameters, enabling production of optimized heat sink designs without requiring complex assembly procedures
Solution Approach 2:
The body part and cooling part are monolithically connected as a single integrated structure produced by additive manufacturing. This merging of components eliminates the need for separate manufacturing and assembly processes, reducing both manufacturing complexity and potential thermal resistance at interfaces
3Ease of operation
If material density is uniform throughout the heat sink, then manufacturing is easier, but airflow and cooling efficiency are reduced
Solution Approach 1:
The heat sink structure exhibits local quality variations where material density is optimized for specific functional requirements at different locations. Regions closer to the heat source have higher density for thermal absorption, while outer regions have lower density to facilitate airflow and convective heat transfer
Solution Approach 2:
The material density parameter changes continuously throughout the heat sink volume, transitioning from a first density value at the heat source interface to a second density value at the outer regions. This gradient distribution optimizes both thermal performance and fluid flow characteristics
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 heat dissipation by evenly distributing thermal distances and increasing airflow, improving cooling efficiency and surface area, thereby reducing thermal resistance and enhancing heat sink performance.
Implementation Method 1
uses 3D CAD data as a digital information source and energy in the form of a high powered laser beam (usually an ytterbium fiber laser) to create three-dimensional metal parts by fusing fine metallic powders together
Implementation Method 2
The laser energy is intense enough to permit full melting (welding) of the particles to form solid metal
Implementation Method 3
a body part with a first surface for contacting the heat generating device; and a cooling part connected to a second surface of the body part and holding a cooling structure
Implementation Method 4
improving cooling efficiency and surface area, thereby reducing thermal resistance
Data Source
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AI summary
A heat sink for cooling a heat generating device comprises a body part with a first surface for contacting the heat generating device, and a second surface contacting a cooling part, and the cooling part including a cooling structure. The structure density of the cooling structure decreases with increasing distance to body part. The cooling structure may be a three dimensional structure e.g. a grid or a lattice, but the cooling structure may also be fins projecting or extending from the second surface of the body part. The heat sink can be manufactured using additive manufacturing e.g. selective laser melting process (SLM). The heat sink can be made of metals e.g. aluminum, copper, ceramics e.g. aluminium nitride (AIN), silicon carbide or a composite containing graphite, graphene or carbon nanotubes.