Heatsink Extension Through PCB Opening for Thermal Management
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Solution Overview
Problem
Conventional thermal via systems in electronic component mounting assemblies often result in high thermal resistance between the component and the heatsink, leading to inefficient heat dissipation and mechanical stress due to differential thermal expansion.
Innovation Solution
A mounting assembly featuring a thermal interface material between the thermal pad and the heatsink extension, which is spatially separated from the circuit board, along with thermal vias and a land for the thermal pad, to reduce thermal resistance and accommodate thermal expansion, while maintaining electrical insulation and mechanical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional thermal via systems are used to transfer heat from the component to the heatsink, then thermal conduction is achieved, but high thermal resistance results leading to inefficient heat dissipation
Solution Approach 1:
The patent extracts the thermal conduction path from the conventional PCB-based thermal via system and creates a separate, dedicated thermal conduction structure. The heatsink extension protrudes through the PCB opening to directly contact the component's lower surface, establishing an independent thermal path that bypasses the high-resistance PCB material and thermal interface material layer, thereby significantly reducing thermal resistance and improving heat dissipation efficiency.
Solution Approach 2:
The patent introduces a thermal conduction structure as an intermediary element between the component and the heatsink base. This structure includes the heatsink extension that protrudes through the PCB and the corresponding opening in the PCB, creating a direct thermal bridge that mediates heat transfer more efficiently than the conventional path through PCB layers and thermal interface material.
2Strength
If the heatsink is directly mounted to the circuit board, then mechanical support is provided, but differential thermal expansion causes mechanical stress
Solution Approach 1:
The patent segments the thermal and mechanical functions by creating a separate thermal conduction path through the heatsink extension that protrudes through the PCB. This segmentation allows the heatsink to be mechanically supported by the PCB mounting holes while the thermal conduction occurs through the protruding extension, decoupling the thermal expansion stresses from the mechanical support structure and reducing overall mechanical stress.
3Reliability
If thermal interface material is used between the component and heatsink, then thermal conduction is achieved, but it adds to the thermal resistance
Solution Approach 1:
The patent transitions from a two-dimensional thermal interface material layer to a three-dimensional thermal conduction structure. The heatsink extension protrudes through the PCB opening to directly contact the component's lower surface, creating a vertical thermal path that eliminates the need for lateral heat spreading through thermal interface material, thereby reducing thermal resistance while maintaining reliable thermal connection.
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 achieves a significant reduction in thermal resistance, allowing for higher power dissipation or increased operating temperature with reduced mechanical stress and extended component lifespan, particularly beneficial in automotive applications.
Implementation Method 1
a mounting assembly featuring a thermal interface material between the thermal pad and the heatsink extension
Implementation Method 2
an array of thermal vias conducting the heat through the PCB material to a thermal interface material mounted on the heatsink material
Implementation Method 3
transfer heat away from the semiconductor package to a heatsink and finally to the ambient
Implementation Method 4
transfer heat away from the semiconductor package to a heatsink and finally to the ambient
Implementation Method 5
accommodate thermal expansion, while maintaining electrical insulation and mechanical contact
Data Source
Figure 1~2
AI summary
A mounting assembly is disclosed which comprises an electronic component (1) mounted on a upper surface of a circuit board (5), comprising at least one electrical connector (2,3) and further comprising a thermal pad (7) provided on a lower surface of the component (1). The circuit board (5) is mounted on a heatsink (10) and provided with an opening (6) beneath the thermal pad (7)of the component (1). The heatsink (10) has a heatsink extension (10a) which extends through the circuit board (5) spatially separated therefrom. A thermal interface material (9) is provided to ensure an electrically insulating thermal connection between the thermal pad (7) and the heatsink extension (10a).