Abstract
This investigation aimed to fabricate a flexible micro resistive temperature sensor to measure the junction temperature of a light emitting diode (LED). The junction temperature is typically measured using a thermal resistance measurement approach. This approach is limited in that no standard regulates the timing of data capture. This work presents a micro temperature sensor that can measure temperature stably and continuously, and has the advantages of being lightweight and able to monitor junction temperatures in real time. Micro-electro-mechanical-systems (MEMS) technologies are employed to minimize the size of a temperature sensor that is constructed on a stainless steel foil substrate (SS-304 with 30 μm thickness). A flexible micro resistive temperature sensor can be fixed between the LED chip and the frame. The junction temperature of the LED can be measured from the linear relationship between the temperature and the resistance. The sensitivity of the micro temperature sensor is 0.059 ± 0.004 Ω/°C. The temperature of the commercial CREE® EZ1000 chip is 119.97 °C when it is thermally stable, as measured using the micro temperature sensor; however, it was 126.9 °C, when measured by thermal resistance measurement. The micro temperature sensor can be used to replace thermal resistance measurement and performs reliably.
Highlights
A light emitting diode (LED) is fabricated from p-type and n-type semiconductor materials, and an input voltage causes the LED chip to glow by combining electron holes and electrons at the p-n junction
The junction temperature of LEDs has been determined from changes in the forward voltage [13]
A flexible micro temperature sensor that could be set between an LED chip and frame was developed, and 30 μm-thick stainless steel foil was used to conduct heat between the LED chip and the frame
Summary
A light emitting diode (LED) is fabricated from p-type and n-type semiconductor materials, and an input voltage causes the LED chip to glow by combining electron holes and electrons at the p-n junction. An LED emits various colors, which are determined by the combined semiconductors. The advantages of an LED over a light-bulb include its small volume, low temperature, low power consumption, long lifetime, fast response and environmental friendliness, whereas the standard lightbulb is limited in terms of high power consumption, ease of breakage and mercury pollution. Eight percent of the input power of an LED is converted to thermal energy; the area of epitaxy is very small, and the heat flux per unit area exceeds that of a central processing unit (CPU). LEDs with a high heat flux output require a strongly conducting radiator, to prevent the destruction of the package of the epitaxy [1]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
