LED Lamp Thermal Management via Exposed Metal Substrate
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Solution Overview
Problem
LED lamps face inefficiencies in heat transfer due to the thermal insulative plastic casing, which limits heat dissipation and leads to increased device temperatures, affecting semiconductor longevity and optical properties.
Innovation Solution
The implementation of a metal substrate with exposed primary and secondary metal plates for enhanced thermal and electrical conductivity, coupled with a heat sink, to create a more efficient heat transfer path outside the casing, reducing thermal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plastic casing is used to enclose the LED structure, then the LED is protected and enclosed, but heat dissipation is limited due to the thermal insulative properties of plastic
Solution Approach 1:
The patent divides the thermal management function into separate components: the plastic casing provides protection while metal plates provide heat dissipation. The casing is segmented to include exposed metal plates that extend beyond the casing, creating distinct thermal management zones.
Solution Approach 2:
The metal plates serve as intermediary elements between the heat-generating LED junction and the external environment. These plates conduct heat away from the LED while being partially exposed outside the insulative plastic casing, acting as a bridge for thermal transfer.
2Ease of operation
If the lead frame is placed within the plastic casing to provide electrical connections, then electrical connectivity is achieved, but heat dissipation is bottlenecked by the leads being sandwiched in the thermally insulative plastic
Solution Approach 1:
The patent extends the thermal management solution into a new spatial dimension by having metal plates protrude outward from the plastic casing. This creates an external thermal pathway that bypasses the insulative plastic barrier, adding a third dimension to heat dissipation routing.
Solution Approach 2:
The invention merges electrical connection functions with enhanced thermal management by using metal plates that serve both as electrical connection points and as primary heat dissipation structures extending beyond the casing.
3Productivity
If high currents are used to drive LED lamps for higher efficiency, then luminous output increases, but device temperatures rise due to insufficient heat transfer from the p-n junction to the ambient environment
Solution Approach 1:
The patent extracts the heat dissipation function from the insulative plastic casing by incorporating exposed metal plates that extend outward. This separates the protective enclosure function from the thermal management function, allowing high-current operation with effective heat removal.
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 configuration significantly improves heat dissipation, reducing device temperatures and maintaining optical performance by allowing for better heat conduction and radiation, thus extending the lifespan of LED lamps.
Implementation Method 1
the main thermal path for heat conduction out of the device is limited by the size of the leads
Implementation Method 2
At the ends of the leads, heat conduction, convection and radiation serve to transfer heat away from the LED when mounted on a printed circuit board
Implementation Method 3
At the ends of the leads, heat conduction, convection and radiation serve to transfer heat away from the LED
Data Source
AI summary
A light-emitting diode (LED) structure with an improved heat transfer path with a lower thermal resistance than conventional LED lamps is provided. For some embodiments, a surface-mountable light-emitting diode structure is provided having an active layer deposited on a substrate directly bonded to a metal plate that is substantially exposed for low thermal resistance by positioning the metal plate at the bottom of the light-emitting diode structure. This metal plate may then be soldered to a printed circuit board (PCB) that includes a heat sink. For some embodiments of the invention, the metal plate is thermally and electrically conductively coupled through several heat conduction layers to a large heat sink that may be included in the structure.