Double Side Cooled Power Overlay Module Using Compliant TIM
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Solution Overview
Problem
Conventional cooling methods for high heat flux power semiconductor devices face challenges in achieving uniform temperature distribution and are costly due to complex manufacturing processes, especially with micro-channel designs that require soldering or brazing operations.
Innovation Solution
A double side cooled power module using power overlay technology with compliant thermal interface materials (TIM) for bonding heat sinks, eliminating the need for soldering or brazing and incorporating micro-channel features for enhanced thermal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional micro-channel cooling designs are used, then heat flux handling capability is improved, but manufacturing complexity and cost increase due to required soldering and brazing operations
Solution Approach 1:
The cooling system is divided into separate substrate assemblies, each with its own integrated micro-channels. This segmentation allows each assembly to be manufactured independently using simpler processes, then joined together, avoiding the need for complex soldering and brazing operations while maintaining effective heat flux handling capability
Solution Approach 2:
A compliant thermal interface material is introduced as an intermediary between the substrate assemblies and heat sinks. This TIM layer simplifies the bonding process by eliminating the need for complex metallurgical joining operations while maintaining effective thermal coupling, thus reducing manufacturing complexity without compromising cooling performance
2Temperature
If known POL technology with smoothing and brazing operations is used, then thermal performance is improved, but manufacturing process complexity increases
Solution Approach 1:
The power module is divided into separate substrate assemblies that can be manufactured independently using simpler processes. Each assembly maintains adequate thermal performance through integrated micro-channels, and the segments are joined using compliant TIM rather than complex brazing operations, thus improving ease of manufacture while preserving thermal performance
Solution Approach 2:
The bonding approach is changed from rigid metallurgical joining (brazing/soldering) to compliant thermal interface material bonding. This parameter change in the bonding method reduces manufacturing process complexity and difficulty while maintaining adequate thermal coupling for effective heat dissipation
3Area of stationary object
If long cooling channels parallel to heated surface are used, then cooling coverage is improved, but temperature uniformity deteriorates due to temperature rise of cooling fluid
Solution Approach 1:
The cooling system is segmented into multiple substrate assemblies with distributed micro-channels. This segmentation creates multiple shorter cooling paths rather than one long channel, allowing better temperature uniformity across the heated surface while maintaining comprehensive cooling coverage through the distributed channel network
Solution Approach 2:
The cooling channel configuration transitions from long parallel channels to a more distributed, multi-dimensional micro-channel network within substrate assemblies. This dimensional change creates shorter thermal paths and better distributes cooling capacity across the surface, improving temperature uniformity while maintaining adequate cooling coverage
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 solution provides efficient thermal management with improved heat flux handling and reduced manufacturing complexity, achieving uniform temperature distribution without compromising cooling channel features.
Implementation Method 1
a second heat sink bonded to the POL solely via a compliant thermal interface material (TIM) opposite the side of the POL bonded to the at least one semiconductor
Data Source
AI summary
A power module includes one or more semiconductor power devices having a power overlay (POL) bonded thereto. A first heat sink is bonded to the semiconductor power devices on a side opposite the POL. A second heat sink is bonded to the POL opposite the side of the POL bonded to the semiconductor power devices. The semiconductor power devices, POL, first channel heat sink, and second channel heat sink together form a double side cooled power overlay module. The second channel heat sink is bonded to the POL solely via a compliant thermal interface material without the need for planarizing, brazing or metallurgical bonding.