New dynamic electro-thermo-optical model of power LEDs

Górecki, Krzysztof; Ptak, Przemysław

doi:10.1016/j.microrel.2018.07.132

Cited by 33 publications

(28 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electrical thermal resistance R the was calculated from the forward voltages at the beginning and at the end of the second measurement step and from the electric power. The real thermal resistance R th was calculated taking into account the optical power P opt and electric power P e value [33,34]. During the measurements, the LED was situated in a light-tight chamber and mounted on the heat exchanger of a forced liquid cooling system, which guarantees the temperature of the substrate remains constant [35].…”

Section: Evaluation Methodsmentioning

confidence: 99%

Application of ZnO Nanoparticles in Sn99Ag0.3Cu0.7-Based Composite Solder Alloys

et al. 2021

Self Cite

View full text Add to dashboard Cite

The properties of Sn99Ag0.3Cu0.7 (SACX0307) solder alloy reinforced with ZnO nanoparticles were investigated. The primary ZnO particle sizes were 50, 100, and 200 nm. They were added to a solder paste at a ratio of 1.0 wt %. The wettability, the void formation, the mechanical strength, and the thermoelectric parameters of the composite solder alloys/joints were investigated. Furthermore, microstructural evaluations were performed using scanning electron and ion microscopy. ZnO nanoparticles decreased the composite solder alloys’ wettability, which yielded increased void formation. Nonetheless, the shear strength and the thermoelectric parameters of the composite solder alloy were the same as those of the SACX0307 reference. This could be explained by the refinement effects of ZnO ceramics both on the Sn grains and on the Ag3Sn and Cu6Sn5 intermetallic grains. This could compensate for the adverse impact of lower wettability. After improving the wettability, using more active fluxes, ZnO composite solder alloys are promising for high-power applications.

show abstract

Section: Evaluation Methodsmentioning

confidence: 99%

Application of ZnO Nanoparticles in Sn99Ag0.3Cu0.7-Based Composite Solder Alloys

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…which can be further simplified to: Figure 14 shows the V F and V rad values of the royal blue and phosphor converted white LEDs measured at different junction temperatures. It was found that the fitting of a quadratic polynomial with A, B, and C coefficients corresponding to Equation (29) obtained an excellent match on the 10 mA to 1000 mA region of the I F total forward current, with an R 2 determination coefficient of around 0.99. [43] or [44].…”

Section: Modeling the Light Output Characteristicsmentioning

confidence: 98%

“…Illuminance, though, is not the property of the LEDs investigated, but it is a property that characterizes a given lighting situation, depending on the emitted total luminous flux of the light source and the geometrical arrangement of the lighting task. In their most recent model version [29] however, Gorecki and Ptak already calculate the primary light output properties: the radiant flux and the luminous flux.…”

Section: The Wider Backgroundmentioning

confidence: 99%

See 1 more Smart Citation

Multi-Domain Modelling of LEDs for Supporting Virtual Prototyping of Luminaires

et al. 2019

View full text Add to dashboard Cite

This paper presents our approaches to chip level multi-domain LED (light emitting diode) modelling, targeting luminaire design in the Industry 4.0 era, to support virtual prototyping of LED luminaires through luminaire level multi-domain simulations. The primary goal of such virtual prototypes is to predict the light output characteristics of LED luminaires under different operating conditions. The key component in such digital twins of a luminaire is an appropriate multi-domain model for packaged LED devices that captures the electrical, thermal, and light output characteristics and their mutual dependence simultaneously and consistently. We developed two such models with this goal in mind that are presented in detail in this paper. The first model is a semi analytical, quasi black-box model that can be implemented on the basis of the built-in diode models of spice-like circuit simulators and a few added controlled sources. Our second presented model is derived from the physics of the operation of today’s power LEDs realized with multiple quantum well heterojunction structures. Both models have been implemented in the form of visual basic macros as well as circuit models suitable for usual spice circuit simulators. The primary test bench for the two circuit models was an LTspice simulation environment. Then, to support the design of different demonstrator luminaires of the Delphi4LED project, a spreadsheet application was developed, which ensured seamless integration of the two models with additional models representing the LED chips’ thermal environment in a luminaire. The usability of our proposed models is demonstrated by real design case studies during which simulated light output characteristics (such as hot lumens) were confirmed by luminaire level physical tests.

show abstract

“…Although there are already complex models that reliably reproduce the behaviour of the LED, taking into account even thermal effects, such as the one reported in [24, 25], these are not easy to implement when a new topology is being proposed, as is the case of several recent works [26–29] that deal with a recurring research topic such as the elimination of the output electrolytic capacitor in rectifiers. However, in the case of LED applications, they keep making the mistake of modelling the load as resistance, since their computations are based only on the voltage and power, ignoring the actual current, which will generate that the actual output ripples do not match those calculated.…”

Section: Introductionmentioning

confidence: 99%