Open AccessStudy of thermal modes of operation of SMD-LEDs in phyto-lamps
Author(s) -
Yuri A. Proshkin,
Alexander Smirnov,
Alexander Sokolov,
Igor M. Dovlatov,
S A Kachan
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/624/1/012091
Subject(s) - thermal resistance , thermal , overheating (electricity) , light emitting diode , materials science , nuclear engineering , radiator (engine cooling) , junction temperature , service life , thermal management of high power leds , led lamp , optoelectronics , mechanical engineering , thermal mass , irradiance , thermal transmittance , environmental science , optics , composite material , engineering , meteorology , electrical engineering , physics
LED phyto-irradiators are promising for use in irradiation systems for growing plants in greenhouses using photoculture technology. Cases, when the thermal calculation of phyto-irradiators is performed incorrectly, have an overheating in the active area of the crystal. It results in faster degradation of the semiconductor, reduces the output luminous flux and the service life of the device. To evaluate and analyze scientific works studying thermal models of LED operating modes, examples of the application of modern methods for determining thermal resistances, to study local heating zones on phyto-irradiator boards when using different types of LEDs and modern thermal imagers to detect soldering defects. The authors classified and analyzed the collected materials according to application criteria and implementation prospects. In the course of the research the authors applied methods of systematic approach. To assess the effectiveness of dissipation of thermal energy released by a LED crystal, they calculate the following parameters: thermal resistance between p-n transition and housing, thermal resistance between housing and PCB, thermal resistance between PCB and the environment. The thermal resistance between the p-n junction and the housing is due to the design of the LED, other parameters are set by the thermal models of the developed lighting devices. The applied methods of cooling do not essentially influence the complexity of thermal models, liquid cooling allows to refuse radiator for the linear thermal model, that slightly raises the accuracy of measurements and simplifies the process of calculation of thermal resistance of transition-housing. The primary role in thermal management of luminaires with SMD elements lies in the following elements: power supply circuits, SMD LED soldering quality and materials used, LED locations, PCB dimensions and location in space, ambient temperature, adequate calculation of thermal resistance between the LED and the environment and selection of radiators.