Tin-Free LED Assembly for Cryogenic Temperature Reliability
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Solution Overview
Problem
Light emitting diodes (LEDs) face issues when operated in extreme cold temperatures, such as failure to heat up for illumination or internal wiring failure, leading to non-functional lighting elements.
Innovation Solution
A light emitting diode design featuring a metal core printed circuit board with solder connections free of tin, using indium and other metals like silver, lead, and bismuth, along with a thermal interface membrane for enhanced thermal conductivity, to maintain functionality at cryogenic temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional solder materials are used in LED lighting elements, then the manufacturing process is simple and cost-effective, but the internal wiring fails in extreme cold temperatures below -50°C
Solution Approach 1:
The patent changes the chemical composition parameters of the solder material by eliminating tin and using alternative alloys (such as silver-based, gold-based, or copper-based solders without tin). This compositional parameter change enables the solder to maintain connection integrity in extreme cold temperatures below -50°C, resolving the reliability issue while managing the complexity through targeted material substitution.
2Temperature
If traditional lighting elements are operated in extreme cold temperatures, then the device structure remains simple, but the lighting element does not heat up to necessary temperature or heats up too slowly
Solution Approach 1:
The patent modifies the thermal and electrical parameters of the lighting element by using tin-free solder materials with different thermal conductivity and electrical resistance characteristics. These parameter changes enable the lighting element to achieve necessary operating temperatures more rapidly and maintain stable illumination in extreme cold environments below -50°C, addressing both the temperature achievement and heating rate issues.
3Reliability
If tin-containing solder is used for connections, then the manufacturing process is straightforward, but the solder joints fail and components separate in cryogenic temperatures below -180°C
Solution Approach 1:
The patent changes the material parameters of the solder by completely eliminating tin and using alternative metal compositions (such as indium-free, tin-free alloys). This parameter change ensures that solder joints remain stable and do not fail in cryogenic temperatures below -180°C, maintaining connection reliability while the manufacturing process remains adaptable through established tin-free soldering techniques.
4Duration of action of stationary object
If conventional lighting elements are used in cold environments, then the device design is simple, but rapid temperature changes cause aging and reduce the life of the circuit board
Solution Approach 1:
The patent modifies the thermal and mechanical parameters of the circuit board assembly by using tin-free solder materials with superior thermal stability and resistance to thermal shock. These parameter changes enable the circuit board to withstand rapid temperature changes without accelerated aging, extending the service life of the lighting element in cold environments while maintaining a relatively simple overall device design.
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 enables LEDs to withstand temperatures below -180°C without component separation and reduces aging due to rapid temperature changes, outperforming traditional methods by maintaining connection integrity and extending the life of the circuit board.
Implementation Method 1
the metal core printed circuit board may comprise at least one lighting element connected to the first planar surface by a third solder which may be free of tin
Implementation Method 2
A light emitting diode design featuring a metal core printed circuit board with solder connections free of tin, using indium and other metals like silver, lead, and bismuth, along with a thermal interface membrane for enhanced thermal conductivity
Data Source
AI summary
It is described herein a light emitting diode (10) which may comprise a metal core printed circuit board (100), a mounting platform, and a thermal interface membrane located between the metal core printed circuit board and the mounting platform. The metal core printed circuit board may comprise at least one resistor (110), at least one lighting element (120), and at least one wire (130). The at least one resistor may be connected to the metal core printed circuit board by a first solder which is free of tin. The at least one wire may be connected to the metal core printed circuit board by a second solder which is free of tin. The at least one lighting element may be connected to the metal core printed circuit board by a third solder which is free of tin.