LpR Article | Jun 20, 2016

Managing Manufacturing and Supply Chain Challenges in LED Luminaire Design by Sanmina

Today’s luminaires are often complicated lighting systems and have a wide range of applications from in-home luminaires and retail to very high power outdoor lighting. This causes several challenges in both design and manufacturing. Some of these problems may have already been solved by design and manufacturing firms having expertise with LED luminaire design and manufacturing. Gelston Howell, Senior Vice President at Sanmina explains how to manage some of these design, manufacturing and supply chain challenges by using examples. Read more »

LpR Article | Jun 20, 2016

Cost Saving Potential with Automation and Well Designed Processes by BJB GmbH

The manufacturing of modern LED luminaires and conventional fixtures has some similarities as well as some distinct differences that result in added challenges. Automation, in combination with a well-conceived product design and process combined with well-matched components, allows for economical manufacturing without compromising production quality and, consequently, reliable, high performance, and high quality luminaires. Olaf Baumeister, Head of Product Development and BJB-Automation at BJB GmbH, explains and discusses technical challenges, successful concepts and solutions. Read more »

LpR Article | Jun 09, 2016

Form Factor Luminaires and Light Effects

If luminaires designed for traditional light sources are simply retrofitted with LED light sources like it occurs in the so-called “1st wave of LEDification”, they will always fall short of expectations in many points. Herbert Weiß and Thomas Noll from Osram GmbH, Martin Möck from the University of Erlangen-Nuremberg, Martin Creusen from Philips Lighting, and Friedhelm Holtz from Insta Elektro GmbH explain why these shortcomings were addressed and which solutions were developed in the EnLight project. Read more »

LpR Article | Jun 08, 2016

DMI Specification Defines Electrical Interface between LED Drivers and Modules

Enabling LED modules and LED drivers to be fully interchangeable at the component level requires a specification for the electrical interface between the driver and module (DMI). Arnulf Rupp of Osram GmbH, a member of both the Zhaga Consortium and MD-SIG, explains the role of both organizations in developing and implementing a consistent, easy to use, cross-vendor DMI specification. Read more »

LpR Article | Technologies | Jun 08, 2016

InGaN Nanowires Make Light Mixing Efficient and Smart

The correlated color temperature (CCT) of high color rendering index (CRI) LED lighting systems can, in principle, be tuned over a wide range. As an alternative approach to conventional phosphor based LEDs, a full-color LED array consisting of red, green and blue (RGB) InGaN based nanowire LEDs monolithically integrated on a micro-scale level has been proposed and fabricated. J. Lee from the Nano Electronics Lab at the Samsung Advanced Institute of Technology, Renjie Wang, Hieu P. T. Nguyen, Ashfiqua T. Connie, Ishiang Shih, and Zetian Mi from the Department of Electrical and Computer Engineering at McGill University in Montreal explain how this technology works and how the three multi-color subpixels on the same chip can be separately biased and can exhibit full-color emission which can be tuned controllably in a wide CCT range. Read more »

LpR Article | Jun 08, 2016

Zhaga Evolves: Focus on Component Standardization Drives New Book Development

With new specifications covering COB LED arrays, LED drivers, and other LED modules and light engines, Zhaga is making rapid progress in standardizing these types of components in response to the needs of the market. Musa Unmehopa, Secretary General of the Zhaga Consortium, and Tim Whitaker, Director of Marketing Communications of the Zhaga Consortium, describe how Zhaga is evolving and changing its focus in a number of areas. Read more »

LpR Article | Research | Jun 08, 2016

A Graphene-Based, Spectrally Tunable, Flexible Field-Effect Light-Emitting Device by the Tsinghua University and the Tsinghua National Laboratory for Information Science and Technology

The continuous tuning of the emission spectrum of a single light-emitting diode (LED) by an external electrical bias is of great technological significance as a crucial property in high-quality displays and may be used in high quality lighting applications, yet this capability has not been demonstrated in existing LEDs. Graphene, a tunable optical platform, is a promising medium to achieve this goal. Xiaomu Wang, He Tian, Mohammad Ali Mohammad, Cheng Li, Can Wu, Yi Yang, and Tian-Ling Ren from the Institute of Microelectronics at the Tsinghua University in Beijing and the Tsinghua National Laboratory for Information Science and Technology (TNList) demonstrate a bright spectrally tunable electroluminescence from blue (~450 nm) to red (~750 nm) at the graphene oxide/reduced-graphene oxide interface. Read more »

LpR Article | Technologies | Jun 08, 2016

Mastering Thermal Issues in LED PCB Design & Laminate Selection by Ventec Europe

LED applications are not the only applications that are driving the need for thermal issues to be considered and mastered in PCB design, but they are certainly amongst the most challenging. Designing LED PCBs requires many considerations and key are those that arise from multiple heat sources in close proximity. Martin Cotton, Director OEM Technology of Ventec Europe describes the process and criteria used when designing PCBs (Printed Circuit Boards) for use in LED applications using thermally conductive IMS (Insulated Metal Substrates). He goes into technical detail with charts and diagrams that explain everything the designer would need to consider when selecting a laminate and commencing a design. Read more »

LpR Article | Jun 07, 2016

Light-Emitting Surface (LES) Concept Enables Comparison of Photometric Properties by Osram GmbH

The concept of the light-emitting surface (LES) has been developed by the Zhaga Consortium to enable comparisons of the photometric properties of different LED light engines. Stefan Lorenz, a Systems Architect with Osram GmbH, describes the theory behind the LES and how it applies to the different Zhaga Books. Read more »

LpR Article | Research | Jun 07, 2016

Al2O3 Coated Europium- Activated Aluminum Silicon Nitride for COB LED Technology by the Graz University of Technology and Tridonic Jennersdorf

Eu2+ activated nitride phosphors have drawn much interest for solid state lighting because of their interesting photoluminescence. While they show excellent optical properties, they are hygroscopic and have the potential of being degraded by atmospheric moisture and high temperatures. A coating layer on the surface is an effective method to improve stability against moisture and oxidation. For use in chip on board technology, Nika Mahne, master student at the Institute of Inorganic Chemistry, A. Reichmann, B. Bitschnau, R. Fischer, from the Graz University of Technology, and F. Schrank from Tridonic Jennersdorf propose an approach where a CaAlSiN3:Eu2+ [1, 2, 3] phosphor was coated with Al2O3, obtained via a Brønsted precipitation reaction based on a solution-coating process from a mixture of aluminum halide with a base after annealing at a temperature of 400°C. Read more »

LpR Article | Technologies | Jun 07, 2016

New Class of Siloxane Polymers for Advanced LED Packaging

Packaging presents a major challenge to further improve LED device efficiency and reliability. A novel class of high stability siloxanes forms a technology platform to address such opportunities in die attach, encapsulation, and light outcoupling applications. Dr. Juha Rantala, CEO & Founder, Dr. Joerg Rockenberger, Director Application & Business Development, Dr. Jyri Paulasaari, Vice President Technology, Dr. Jarkko Heikkinen, Director Inks & Pastes. Markus Laukkanen, Application Manager, and Dr. Janne Kylmä, Vice President Engineering & Production at Inkron Oy explain the material properties and give examples of how these new materials in combination with novel nanomaterials enable products fully compatible with current process tools and flows while having superior properties. Read more »

LpR Article | Research | Jun 07, 2016

Flexible OLEDs for Lighting Applications by the Holst Centre

While OLEDs already have successfully found their way into display applications, the breakthrough in lighting applications is still pending. The reasons are diverse, but cost is one major point. Another reason is the current edge of inorganic LEDs giving reasonable design opportunities in many standard applications. However, there are applications where OLEDs could score, especially the flexible OLEDs. But even these OLEDs need to become cheaper to be applied widely. The Holst Centre and partners aim to develop generic technologies for large area flexible OLEDs which can be processed with roll-to-roll (R2R) technology. Process Engineer Tansim Baig gives an example and an overview of the current status of the development. Read more »

LpR Article | Jun 07, 2016

Boost-Buck LED Driver Topology for Low Input and Output Ripple for Low EMI by Linear Technology

Many automotive LED driver circuits require constant-current DC/DC converter topologies that can both step-up and step-down the input-to-output voltage. Out of the commonly used step-up and step-down topologies, those that produce low EMI are the most desirable. Keith Szolusha, applications engineering section leader with Linear Technology, proposes a new boost-buck (boost-then-buck-mode) floating output LED driver to satisfy these requirements. Read more »

LpR Article | Jun 06, 2016

Predictive Simulation to Virtually Test Product Design and Reduce Time to Market by Trinseo

With technical progress and new regulations, shorter product cycles are a continuous challenge for OEMs. Modelling is one measure to cut time to market efficiently without compromising product quality. Trinseo Technical Service & Development specialists Kersten Terry and Berend Hoek explain the process of computer-based simulation, specifically applied to injection molded plastic parts. Through case studies, they showcase how Trinseo’s Application Engineering Development resource facilitates more effective LED-lighting development relative to part design, tool design and material selection by modelling “real world“ performance. Read more »

LpR Article | Jun 06, 2016

The Role of Special Optics in Human Centric Lighting and Architecture by Suleyman Turgut and Luminit LLC

While Human Centric Lighting is relatively new and a topic of some debate, few can argue over the benefits of creating more natural lighting conditions in offices, retail spaces and other architectural settings. Anthony Ang, Optical Engineer, Suleyman Turgut, Director of Sales, and Mary Ann Giorgio, Marketing Communications Specialist at Luminit LLC show how special or “tertiary” optics, such as diffuser and direction film, can play a crucial role in Human Centric Lighting or lighting that takes into account the emotional and biological needs of humans. Read more »

LpR Article | Trends | Jun 06, 2016

Embedded Lighting - Developing New Lighting Applications for Modern Architectural Projects by Philips Lighting

When the era of LED lighting started, everybody talked about the new age of lighting with new opportunities. While many lighting concepts are still pure replacements of the conventional light sources, with the maturation of this technology, more and more new concepts are realized, and the future perspectives are even more exciting. Brad Koerner, Venture Manager - Philips Luminous Patterns at Philips Lighting, shows examples, explains why such new concepts are desirable, and discusses which technologies support the introduction of new lighting applications. Read more »

LpR Article | Research | Jun 03, 2016

Luminescent Glasses and Glass Ceramics for White Light Emitting Diodes by the Fraunhofer Institute and the South Westphalia University of Applied Science

Luminescent glasses or glass ceramics represent an interesting alternative to LED phosphor due to their high thermal and chemical stability. A series of rare-earth doped glasses are investigated for their potential application as photon converters for solid-state lighting applications. Franziska Steudel, Sebastian Loos, Bernd Ahrens, and Stefan Schweizer from the Fraunhofer Institute and the South Westphalia University of Applied Science respectively, show that the color coordinate of double-doped glass can be varied over a broad spectral range by changing the rare-earth doping ratio accordingly. In addition, double-doping allows for a change in the color coordinate by using different excitation wavelengths. Read more »

LpR Article | Jun 03, 2016

More Efficient Plant Growth with Quantum Dots by Nanoco Lighting

Using LEDs for plant growth lights is nothing new, nor is the use of QDs in LED lighting. While it is already proven that LED systems have big advantages over conventional plant lighting technologies, it is not common knowledge that Cd-free QDs are ideal candidates for optimizing the light spectrum for plant growth systems. Dale Needham, Business Development Director-Lighting at Nanoco Lighting, explains the opportunities and advantages based on Nanoco’s proprietary and patentprotected CFQD® cadmium-free quantum dot LED grow lighting systems. Read more »

LpR Article | Technologies | Jun 03, 2016

Cost and Performance Optimization of Thermal Management Solution for High Power LEDs by Cambridge Nanotherm

The LED industry has a challenge. General lighting requires very bright LEDs that can replace incandescent and halogen lights. Manufacturers need efficacy, cost and manufacturability to be “just right” but most leading solutions, especially in thermal management, are short of the mark. Giles Humpston, applications engineer, Cambridge Nanotherm, discusses ways to combine performance with reasonable costs and good manufacturability. Read more »

LpR Article | Jun 03, 2016

Potting Processes as a Part of LED-Based Lighting Module Manufacturing Methods by ViscoTec Pumpen and Dosiertechnik GmbH

Many manufacturing processes need very accurate dosing. One such dosing process concerns the potting of LED-modules. Numerous parameters affect the potting quality. Willi Huber from the Business Unit Adhesives & Chemicals at ViscoTec Pumpen- u. Dosiertechnik GmbH explains casting equipment, critical parameters and appropriate potting methods. Read more »

Resources | LpR Article | Event-Reports | Trends | May 30, 2016

Light + Building Post Show Report: The Six Most Noteworthy Observations by LED professional

In the weeks and months before the show it was obvious that the major topics were going to be IoT and connectivity. There are many reasons for this. One is that LED lighting has become established but the big deals for smart lighting and human centric lighting are missing. IoT seems to be the way to improve communication and enable both smart lighting and HCL. Arno Grabher-Meyer from LED professional gives a summary of his impressions of the fair in regards to these topics, and beyond. Read more »

LpR Article | May 24, 2016

Power over Ethernet Lighting for Commercial Buildings by Molex

Today, information technology (IT) and lighting are separate worlds. It is necessary to create a bridge between these worlds, not only from a technical standpoint but also from the perspective of understanding what is important to each industry. Giovanni Frezza, Group Product Manager at Molex, discusses how LEDs and PoE may pave the way with new power standards: LEDs far outperform the lumens output of older lighting technologies. Today, the PoE standard for LED is 30 W. An UPOE standard for 60 W is in the works, and an expansion called BP is in progress for up to 95 W. Read more »

LpR Article | Research | May 24, 2016

Thin-Film Light Management System for Intelligent Large-Area LED Luminaires by the Centre Suisse d’Electronique et de Microtechnique SA

The recent advances in Solid State Lighting have triggered the development of smart lighting solutions. However, the point-like nature of LEDs imposes the use of inefficient and/or bulky light scattering sheets or costly, short-pitch LED arrays to achieve acceptable spatial luminance uniformity. Ph.D. Oscar Fernandez, Senior R&D Engineer at the Centre Suisse d’Electronique et de Microtechnique SA (CSEM) shows a new approach in the form of an innovative thin form-factor light management (LM) system comprising a highly engineered combination of thin-film diffractive nano-optical and refractive micro-optical elements. Read more »

LpR Article | May 24, 2016

The Value of Dark Skies - About Environmentally Friendly Lighting by the International Dark-Sky Association (IDA)

For many years no one worried about light pollution: on the contrary, the brighter the better. Then it became evident that darkness also has its value. J. Scott Feierabend, executive director of the International Dark-Sky Association (IDA), presents and explains in detail, the latest findings and suggestions published in the “New IDA LED Lighting Practical Guide” and “New IDA Standards on Blue Light at Night”. He also discusses how to illuminate public areas while avoiding excess light pollution. Read more »

LpR Article | Technologies | May 24, 2016

Create Colorful and Bright LED Light with an LED Matrix Dimmer by Linear Technology

RGB LEDs are quite common and used in many applications today. More advanced multi-color solutions like RGBW, RGBA or RGBWA offer huge advantages over RGB solutions, but several aspects are more complicated. Keith Szolusha, applications engineering section leader for power products at Linear Technology explains the advantages of RGBW systems, how they work, how to set up such systems, and how to drive them correctly using Linear Technology’s LT3965 8-switch LED matrix dimmer in combination with the LT3952 boost-buck LED driver as an example. Read more »

LpR Article | May 24, 2016

Safety Concept for LED Street Lighting by Phoenix Contact

Street and building lighting has profited greatly from the advantages of LED technology. While modern LED lampposts have dielectric strengths of up to 6 kV, surge currents and voltages occurring in the grid can be significantly higher. Andreas Schamber, Product Manager for surge protection at Phoenix Contact, presents and discusses a comprehensive power surge protection concept to prevent blackouts during power surges and to protect investments in LED lighting based on the company’s product portfolio. Read more »

LpR Article | Technologies | May 19, 2016

3-Pad LED Flip Chip COB by Flip Chip Opto

Wafer level packaging and flip chip design are the most recent trends in LED manufacturing and packaging. These LED types are perfectly suited for producing COB modules. This combination already promises better thermal performance than standard SMD package based products. However, there is still room for improvements. Pao Chen, Director of Research and Development at Flip Chip Opto shows how a 3-pad flip chip LED further reduces thermal resistance, allows higher power and can help to reduce costs. Read more »

LpR Article | Research | May 17, 2016

Human-Focused Outdoor Illumination: Trade-Off Between Pleasing Color and Circadian Action, by the Vilnius University

A smart RGBA solid-state light engine with tunable correlated color temperature (CCT) and high-fidelity color rendition was applied for the validation of the Kruithof hypothesis in several outdoor environments. Subjects were asked to find the most “pleasing” illumination conditions by performing a CCT adjustment. Maintaining constant illuminance, the mean selected CCT was found to increase from about 3000±200 K at 5 lx to about 3500±250 K at 50 lx almost independently of the content of the viewed scene. Dr. Pranciškus Vitta, Head of Lighting and Electronics System Lab at the Vilnius University shows that this increase is statistically significant and provides qualitative validation of the Kruithof hypothesis in outdoor environments, but with the intervals of CCT for “pleasing” illumination, it is substantially broader and shifted to higher values. Read more »

LpR Article | May 11, 2016

230 VAC Driven LED Modules with Strongly Reduced Flicker, by euroLighting

One of the continuing trends in LED lighting is toward AC driven LED modules. Big progress has been made regarding dimmability and reduction of flicker. However, there are still differences in the various concepts that lead to very different results. Wolfgang Endrich, founder and managing director of euroLighting presents a recently improved new concept to significantly reduce flicker. Read more »

LpR Article | May 09, 2016

White Hybrid Light-Emitting Diodes: A Plausible Solution for Commercialization and Health Issues, by the University of Erlangen-Nuremberg (FAU)

One of the challenges in terms of commercialization of white LEDs is the need for cheap, inorganic phosphors. In this context, hybrid LEDs have recently emerged as a new approach based on downconverting organic coatings. The authors, Pedro B. Coto from the Institute for Theoretical Physics, Marlene Pröschel and Uwe Sonnewald from the Department of Biology, and Lukas Niklaus, Michael D. Weber and Rubén D. Costa from the Department of Chemistry and Pharmacy at the University of Erlangen-Nuremberg (FAU), describe this technology and cover recent breakthroughs and their prospects. Read more »