Solid State Power Switch Heat Sink Configuration
Solution Overview
Problem
High current electrical switches face challenges in heat management, as they generate excessive heat when carrying high currents, leading to potential damage due to inadequate heat dissipation, especially when cables are undersized for the expected current ratings, resulting in reversed heat flow and temperature increases.
Innovation Solution
The design incorporates a short high electrical current path with high conductivity and a direct heat conduction path to a thermally conductive heat sink using a bus bar thermal bridge and thermally conductive interface material, ensuring efficient heat transfer away from heat-generating components and reducing the risk of thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cables are selected based only on maximum continuous current rating, then cable cost is reduced, but heat dissipation capability is insufficient leading to excessive switch temperature
Solution Approach 1:
The patent extracts the heat dissipation function from the cable and assigns it to a dedicated heat sink. The cable is sized only for current carrying capacity, while the heat sink handles thermal management. This separation allows the cable to be smaller and cheaper while the heat sink provides sufficient heat dissipation capability.
Solution Approach 2:
The patent introduces a heat sink as an intermediary component between the switch and the ambient environment. This heat sink acts as a thermal mediator that efficiently conducts heat away from the switch components, enabling better heat dissipation without requiring oversized cables.
2Loss of energy
If cable size is increased to improve heat dissipation, then heat transfer capability is improved, but cost of metal material increases
Solution Approach 1:
The patent extracts the heat dissipation function from the cable and assigns it to a dedicated heat sink. The cable is sized only for current carrying capacity, while the heat sink handles thermal management. This separation allows the cable to be smaller and cheaper while the heat sink provides sufficient heat dissipation capability.
Solution Approach 2:
The heat sink serves multiple functions: it acts as a thermal management component for the switch, provides a mounting structure for the switch, and facilitates heat dissipation to the ambient environment. This multi-functionality consolidates what would otherwise require multiple separate components.
3Object-generated harmful factors
If interface resistance between cable terminals and switch terminals is reduced, then heat generation is reduced, but manufacturing cost increases
Solution Approach 1:
The patent acknowledges that some heat generation at interfaces is inevitable, but converts this potential harm into a benefit by designing the heat sink to efficiently capture and dissipate this heat. The heat that would otherwise damage components is redirected to the heat sink, allowing standard manufacturing practices to be used without requiring expensive low-resistance interfaces.
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 solution effectively maintains the switch and connected components at safe temperatures, allowing operation beyond rated maximum continuous current without damage, reducing energy consumption and material costs by using less expensive switching devices and preventing heat from being transferred back into cables.
Implementation Method 1
a direct heat conduction path to a thermally conductive heat sink using a bus bar thermal bridge and thermally conductive interface material
Implementation Method 2
a thermally conductive heat sink... ensuring efficient heat transfer away from heat-generating components
Data Source
AI summary
A high current, solid state, electrical switch has switch terminal blocks on opposite sides of one or more arrays of parallel connected, solid state, high current, power switching devices mounted on a support. A first terminal of each switching device of each array is directly electrically and thermally bonded to a switch terminal block. A bus bar thermal bridge is directly electrically and thermally bonded to a second terminal of the switching device of each array. A thermally conductive heat sink panel is contoured in alignment with, and has a surface in spaced juxtaposition from, a surface of the bus bar thermal bridge and from surfaces of each of the switch terminal blocks. A thermally conductive, electrically insulating thermal interface material thermally contacts and extends between all said surfaces for conducting heat from the switch terminal blocks and from the thermal bridge to the heat sink panel.