Packaging of High Brightness, Big-Chip LEDs

2011 ◽  
Vol 2011 (DPC) ◽  
pp. 001472-001492
Author(s):  
Lidia Lee ◽  
Paul Panaccione
Keyword(s):  
Form Factor ◽  
System Design ◽  
Light Output ◽  
Large Area ◽  
Plug And Play ◽  
High Brightness ◽  
Package Design ◽  
System Requirements ◽  
Lighting Systems ◽  
The Impact

A common approach for designing HB-LEDs into a variety of lighting systems is to arrange an array of many emitters over a large area in order to provide the required photometric flux. In certain applications, this common approach of arraying a large number of small chip LEDs introduces a number of challenges that can be solved by using a single package of big-chip LEDs with enough light output to meet the system requirements. This presentation will discuss package design for big-chip LEDs, compared to an array of many small emitter packages. In addition to big-chip package design, the impact on system design including optics, drivers, thermals, reliability, and form factor will be addressed. For illustration, a reference example will be presented in detail, consisting of an easy to use plug and play single package with 36mm2 of emitting area capable of up to 6000 lumens.

Solutions for Wafer-Level Packaging of High Brightness LEDs

2011 ◽  
Vol 2011 (DPC) ◽  
pp. 001418-001442
Author(s):  
Thomas Uhrmann ◽  
B. Kim ◽  
T. Matthias ◽  
P. Lindner
Keyword(s):  
Form Factor ◽  
Light Output ◽  
High Volume ◽  
Performance Ratio ◽  
High Yield ◽  
Light Sources ◽  
Wafer Level ◽  
Process Step ◽  
High Brightness ◽  
The Cost

High brightness LEDs (HB-LEDs) carry a high prospect for general lighting applications. Competing with the cost/performance ratio of current light sources demands an increase of the overall efficiency as well as the reduction of the device cost. Since packaging accounts for 30%–50% of the cost of HB LED manufacturing, moving from die- level to wafer-level processes is one likely potential solution for reducing cost per lumen. Silicon-based WLP, using the established processing technology of the MEMS and IC industry, offers high fabrication reliability, high yield and the direct integration of the driver IC in the package. The already small form factor of WLP can be further reduced using Through-Silicon-Vias (TSV), increasing the maximum amount of chips per wafer. Silicon WLP also offers superior thermal management, with the relatively high thermal conductance of silicon. Redistributing LED dies on silicon wafer submounts, with metal bonding and copper TSVs, further improves the heat conductance away from the active region of the chip, resulting in increased device performance. Wafer-level optics can further improve performance and reduce packaging costs. Wafer-level lens molding based on imprint lithography is in high volume manufacture for cell phone camera modules. It allows creation of spherical and a-spherical lenses as well as lens stacks with minimized form factor. In contrast to the currently applied drop dispensing technique for LED lens fabrication, the shape of the lens can be accurately tailored and the decrease of the lens size results in lower absorption and higher light output. Most of these technologies are already in high volume production in other sectors. We will discuss the field proven solutions at each process step, from the formation of the silicon interposer, through the chip-to-wafer bonding, to the final imprinting of the wafer-level optics.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

Luminous Environment and the Perceived Environment

2019 ◽  
pp. 15-21
Author(s):  
Banu Manav
Keyword(s):  
Experimental Studies ◽  
Light Output ◽  
Lighting Design ◽  
Lighting System ◽  
Main Concept ◽  
Healthy Environment ◽  
Perceived Environment ◽  
Efficiency Cost ◽  
Lighting Systems ◽  
User Friendly

In lighting design, the main concept is to achieve a healthy environment, which addresses energy efficiency, cost, maintenance, and quality. User-friendly lighting systems shall be adopted to architecture and interior architecture. User control over the lighting system is important, by dimming or increasing light output, by changing the colour of the light sets the inner atmosphere and affects user mood. Standards and codes on lighting shall also be evaluated by means of these topics. The paper aims to analyse how the luminous environment is affective on the perceived environment. Hence, a series of experimental studies and recent research will be evaluated in regard to understanding and designing luminous environment.

Lighting energy performance determination in office environments through implementation of EN 15193-1 for Turkey

2021 ◽  
pp. 147715352098742
Author(s):  
FŞ Yilmaz
Keyword(s):  
System Design ◽  
Architectural Design ◽  
Office Buildings ◽  
Energy Requirements ◽  
System Control ◽  
Lighting System ◽  
Artificial Lighting ◽  
Design Alternatives ◽  
Lighting Energy ◽  
The Impact

Office buildings are building typologies where efficient and optimal use of lighting energy is crucial while providing comfortable visual environments. The purpose of this study is to explore the impact of diverse architectural design alternatives on lighting energy requirements and lighting energy saving possibilities through a case study. In this study, a total of 3888 design alternatives are investigated in a comparative way in terms of daylighting system design alternatives, artificial lighting system design scenarios, artificial lighting system control types and shading system control options. Introducing the adaptation process of the EN 15193-1:2017 standard for Turkey’s specific climatic and geographical conditions and considering diverse lighting design scenarios, results of this parametric study aim to underline the significance of architectural design strategies in office buildings for the reduction of lighting energy requirements.

scholarly journals Renovation of Public Lighting Systems in Cultural Landscapes: Lighting and Energy Performance and Their Impact on Nightscapes

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 509
Author(s):  
Lodovica Valetti ◽  
Francesca Floris ◽  
Anna Pellegrino
Keyword(s):  
Energy Efficient ◽  
Flux Distribution ◽  
Cultural Landscapes ◽  
Energy Performance ◽  
Luminous Flux ◽  
Landscape Value ◽  
Reduce Energy Consumption ◽  
Lighting Systems ◽  
The Impact ◽  
Positive Effect

The technological innovation in the field of lighting and the need to reduce energy consumption connected to public lighting are leading many municipalities to undertake the renewal of public lighting systems, by replacing the existing luminaires with LED technologies. This renovation process is usually aimed at increasing energy efficiency and reducing maintenance costs, whist improving the lighting performance. To achieve these results, the new luminaires are often characterised by a luminous flux distribution much more downward oriented, which may remarkably influence and alter the perception of the night image of the sites. In this study the implications of the renovation of public lighting systems in terms of lighting and energy performance as well as the effects relating to the alteration of the night image, in historical contexts characterized by significant landscape value, are analysed. Results, along with demonstrating the positive effect that more sustainable and energy efficient lighting systems may have on the lighting performance and energy consumptions of public lighting systems, evidences the impact they may have on the alteration of the nocturnal image.

scholarly journals Monitoring the Impact of the Large Building Investments on the Neighborhood

2021 ◽  
Vol 11 (14) ◽  
pp. 6537
Author(s):  
Marian Łupieżowiec
Keyword(s):  
Groundwater Level ◽  
Soil Improvement ◽  
Deep Excavation ◽  
Large Area ◽  
Safety Measures ◽  
High Rise ◽  
The Impact ◽  
Large Building ◽  
Additional Safety ◽  
Made In

The article presents the concept of monitoring buildings and infrastructure elements located near large construction investments (the construction of high-rise buildings of the Oak Terraces housing estate in Katowice and the construction of a tunnel under the roundabout in Katowice along the intercity express road DTŚ). The impacts include deep excavation, lowering of the groundwater level over a large area, and dynamic influences related to the use of impact methods of soil improvement. The presented monitoring includes observation of the groundwater level with the use of piezometers, geodetic measurements of settlement and inclinations, as well as the measurement of vibration amplitudes generated during the works involving shocks and vibrations. It was also important to observe the development of cracks on the basis of a previously made inventory of damage. The results of the monitoring allow corrections to be made in the technology of works (e.g., reduction of vibration amplitudes, application of additional protections at excavations, etc.) or the use additional safety measures. Currently, there are also monitoring systems used during the operation of completed facilities.

News personalization for peace: how algorithmic recommendations can impact conflict coverage

2019 ◽  
Vol 30 (3) ◽  
pp. 309-328 ◽  
Author(s):  
Mariella Bastian ◽  
Mykola Makhortykh ◽  
Tom Dobber
Keyword(s):  
Conceptual Framework ◽  
System Design ◽  
News Media ◽  
Content Distribution ◽  
Content Type ◽  
Constructive Conflict ◽  
Peace Journalism ◽  
Negative Impacts ◽  
The Impact ◽  
War Reporting

PurposeThe purpose of this paper is to develop a conceptual framework for assessing what are the possibilities and pitfalls of using algorithmic systems of news personalization – i.e. the tailoring of individualized news feeds based on users’ information preferences – for constructive conflict coverage in the context of peace journalism, a journalistic paradigm calling for more diversified and creative war reporting.Design/methodology/approachThe paper provides a critical review of existing research on peace journalism and algorithmic news personalization, and analyzes the intersections between the two concepts. Specifically, it identifies recurring pitfalls of peace journalism based on empirical research on constructive conflict coverage and then introduces a conceptual framework for analyzing to what degree these pitfalls can be mediated – or worsened – through algorithmic system design.FindingsThe findings suggest that AI-driven distribution technologies can facilitate constructive war reporting, in particular by countering the effects of journalists’ self-censorship and by diversifying conflict coverage. The implementation of these goals, however, depends on multiple system design solutions, thus resonating with current calls for more responsible and value-sensitive algorithmic design in the domain of news media. Additionally, our observations emphasize the importance of developing new algorithmic literacies among journalists both to realize the positive potential of AI for promoting peace and to increase the awareness of possible negative impacts of new systems of content distribution.Originality/valueThe article particle is the first to provide a comprehensive conceptualization of the impact of new content distribution techniques on constructive conflict coverage in the context of peace journalism. It also offers a novel conceptual framing for assessing the impact of algorithmic news personalization on reporting traumatic and polarizing events, such as wars and violence.

Assessing the impact of the transition to Light Emitting Diodes based solar lighting systems in India

2013 ◽  
Vol 17 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Santosh M. Harish ◽  
Shuba V. Raghavan ◽  
Milind Kandlikar ◽  
Gireesh Shrimali
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Solar Lighting ◽  
Lighting Systems ◽  
The Impact

scholarly journals High-performance large-area quasi-2D perovskite light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Changjiu Sun ◽  
Yuanzhi Jiang ◽  
Minghuan Cui ◽  
Lu Qiao ◽  
Junli Wei ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diodes ◽  
Intermediate Phase ◽  
Formation Enthalpy ◽  
Phase Segregation ◽  
Phase Changes ◽  
Large Area ◽  
High Brightness ◽  
Light Emitting ◽  
Performance Decline

AbstractSerious performance decline arose for perovskite light-emitting diodes (PeLEDs) once the active area was enlarged. Here we investigate the failure mechanism of the widespread active film fabrication method; and ascribe severe phase-segregation to be the reason. We thereby introduce L-Norvaline to construct a COO−-coordinated intermediate phase with low formation enthalpy. The new intermediate phase changes the crystallization pathway, thereby suppressing the phase-segregation. Accordingly, high-quality large-area quasi-2D films with desirable properties are obtained. Based on this, we further rationally adjusted films’ recombination kinetics. We reported a series of highly-efficient green quasi-2D PeLEDs with active areas of 9.0 cm2. The peak EQE of 16.4% is achieved in <n > = 3, represent the most efficient large-area PeLEDs yet. Meanwhile, high brightness device with luminance up to 9.1 × 104 cd m−2 has achieved in <n> = 10 film.

Deepwater Steel Catenary Riser System Design for Lingshui 17-2 Project

2021 ◽  
Author(s):  
Ning He ◽  
Hu Yang ◽  
Fanli Xu ◽  
Yongming Cheng
Keyword(s):  
South China Sea ◽  
System Design ◽  
South China ◽  
Oil And Gas ◽  
Low Cost ◽  
Northern South China Sea ◽  
Steel Catenary Riser ◽  
China Sea ◽  
Scr System ◽  
The Impact

Abstract A riser is a key component for transporting produced oil and gas from the subsea wells to the surface production vessel. Through nearly 30 years of design and implementation, Steel Catenary Risers (SCRs) have been found to have the advantages of relatively low cost and good adaptability to floating platform’s motion. This paper investigates deepwater SCR system design for the Lingshui 17-2 (termed LS17-2) project. This paper first introduces a SCR system for the LS17-2 project. The field for this project is located in the northern South China Sea, with water depth of 1220m to 1560m. LS17-2 consists of a subsea production system, a deep-draft semi-submersible (SEMI), and an export riser/pipeline. The platform was designed to have a large storage capacity with a variable draft during its operation. Based on deepwater SCR engineering experience, the key SCR design challenges are summarized from the engineering executive perspective. The challenges to the SCR system design for the LS17-2 project include harsh environment condition in South China Sea and the impact on fatigue design for the requirement of 30-years’ service life. They call for design optimization and innovative ideas. The engineering design and analysis are discussed together solutions. To demonstrate the deepwater SCR system design for LS17-2 project, examples are provided to illustrate the challenges and solutions. The experience learned from this paper should have significant relevance to future SCR design.

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