Segmented Cooling Apparatus for Microelectronic Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cooling technologies for high-performance microelectronic devices face limitations due to the need for materials with high thermal conductivity and low coefficient of thermal expansion (CTE) to manage thermal stress and efficiency, with existing solutions being either costly or insufficient for future chip designs.
Innovation Solution
A cooling apparatus comprising a rigid support ring, a mechanically resilient thermally conductive membrane with thermally conductive posts that allow for efficient heat transfer while accommodating thermal expansion, using materials like copper-tellurium alloy and beryllium-copper spring alloy to minimize thermal stress and enhance thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper is used as heat spreader material, then thermal conductivity is improved, but coefficient of thermal expansion mismatch causes warping and damage to chip
Solution Approach 1:
The heat spreader is divided into multiple discrete heat spreader elements (first, second, third elements) with different material compositions and thermal expansion coefficients. Each element is positioned at specific locations on the chip where local thermal expansion characteristics differ, allowing each segment to accommodate local stress requirements while collectively providing thermal management across the entire chip surface.
Solution Approach 2:
Different regions of the chip receive heat spreader elements with locally optimized properties. The first heat spreader element has different thermal expansion coefficient than the second and third elements, matching the local requirements of different chip regions. This local customization allows each area to experience minimal thermal stress while maintaining effective heat transfer.
2Object-affected harmful factors
If compliant die attach material is used to reduce thermal stress, then chip damage is reduced, but thermal resistance increases and thermal performance decreases
Solution Approach 1:
The heat spreader is segmented into multiple elements with varying thermal expansion coefficients, allowing each segment to independently accommodate thermal expansion differences without requiring compliant die attach material. This rigid-to-rigid connection maintains low thermal resistance while the segmented structure provides stress accommodation.
Solution Approach 2:
The invention changes the thermal expansion coefficient parameter of the heat spreader elements to match the chip's thermal expansion characteristics. By selecting materials with appropriate thermal expansion coefficients for each heat spreader element, the system achieves both stress compatibility and high thermal conductivity without needing compliant die attach materials.
3Power
If high power chip cooling is implemented, then chip performance is improved, but thermal flux increases beyond conventional heat sink capability
Solution Approach 1:
The heat dissipation function is segmented across multiple heat spreader elements positioned at different locations on the chip. Each element manages thermal flux from specific high-power regions, distributing the total thermal load across multiple pathways to the heat sink, thereby handling higher overall power dissipation effectively.
Solution Approach 2:
Heat spreader elements with locally optimized thermal and mechanical properties are positioned at specific high-heat-generation regions on the chip. This local optimization ensures efficient heat extraction from hot spots while accommodating local thermal expansion, enabling the system to handle increased power densities.
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 apparatus provides effective thermal management by maintaining low thermal expansion and high conductivity, enabling efficient heat dissipation without inducing damaging stresses on microelectronic devices, thus supporting the progression to smaller and faster chip designs.
Implementation Method 1
heat transferred from the microelectronic device to the bottom surface of the membrane may be transferred to the multiplicity of thermally conductive posts
Implementation Method 2
mechanically resilient, thermally conductive bottom membrane... accommodating thermal expansion
Implementation Method 3
mechanically resilient... bottom membrane having a top and a bottom surface, wherein the top surface of the membrane is attached to the bottom surface of the ring
Data Source
AI summary
One embodiment of the present invention is an apparatus for cooling a microelectronic device including: (a) a rigid support ring having a top surface and a bottom surface; (b) a mechanically resilient, thermally conductive bottom membrane having a top and a bottom surface, wherein the top surface of the membrane is attached to the bottom surface of the ring; and (c) a multiplicity of thermally conductive posts having top and bottom surfaces, the posts being disposed with their bottom surfaces in thermal contact with the top surface of the bottom membrane over an area, wherein the posts are arrayed in the area with spaces therebetween so that heat transferred from the microelectronic device to the bottom surface of the membrane may be transferred to the multiplicity of thermally conductive posts.