Articles & Interviews

LpR Article | Jun 06, 2016
The Role of Special Optics in Human Centric Lighting and Architecture by Suleyman Turgut and Luminit LLC
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 | Jun 06, 2016
Predictive Simulation to Virtually Test Product Design and Reduce Time to Market by Trinseo
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 07, 2016
Boost-Buck LED Driver Topology for Low Input and Output Ripple for Low EMI by Linear Technology
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 | Research | Jun 07, 2016
Flexible OLEDs for Lighting Applications by the Holst Centre
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 | Technologies | Jun 07, 2016
New Class of Siloxane Polymers for Advanced LED Packaging
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
Al2O3 Coated Europium- Activated Aluminum Silicon Nitride for COB LED Technology by the Graz University of Technology and Tridonic Jennersdorf
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 08, 2016
Mastering Thermal Issues in LED PCB Design & Laminate Selection by Ventec Europe
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 | 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
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 | Jun 08, 2016
Zhaga Evolves: Focus on Component Standardization Drives New Book Development
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 | Technologies | Jun 08, 2016
InGaN Nanowires Make Light Mixing Efficient and Smart
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
DMI Specification Defines Electrical Interface between LED Drivers and Modules
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 | Jun 09, 2016
Form Factor Luminaires and Light Effects
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 »
Research | Jun 09, 2016
Blue Wavelengths of LED Light Negatively Affect Milk Quality
Blue Wavelengths of LED Light Negatively Affect Milk Quality Matt Hayes, managing editor and social media officer for the College of Agriculture and Life Sciences, and Alina Stelick, research support specialist in the Department of Food Science, report at the Cornell Chronicle of June 8th, 2016 that Cornell researchers in the Department of Food Science found exposure to light-emitting diode (LED) sources for even a few hours degrades the perceived quality of milk more so than the microbial content that naturally accumulates over time. Their study determined milk remained at high-quality for two weeks when shielded from LED exposure, and consumers overwhelmingly preferred the older, shielded milk over fresh milk stored in a typical container that had been exposed to LED light for as little as four hours. Read more »
LpR Article | Jun 20, 2016
Cost Saving Potential with Automation and Well Designed Processes by BJB GmbH
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 20, 2016
Managing Manufacturing and Supply Chain Challenges in LED Luminaire Design by Sanmina
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
Advanced Optical Plastics Materials for LED Lighting Applications by Styron LLC
Advanced Optical Plastics Materials for LED Lighting Applications by Styron LLC Across a range of lighting solutions, Light Emitting Diodes have emerged as the clear choice for industry and consumers alike. Government regulations and consumer preference for more environmentally-conscious, energy-efficient products have caused manufacturers to develop solutions for the marketplace that offer new levels of energy efficiency, durability and long life. While the technology has evolved, so have the materials that go into the finished product. Claude Van Nuffel, Eric Wu, Peter Jackson and Marta Sans Peña from Styron LLC discuss versatility and one-of-a-kind properties of plastic – especially polycarbonate and polycarbonate blends – and why they have become the “materials of choice”. Read more »
LpR Article | Jun 20, 2016
Development of a Workflow for Colored Ray Data by TechnoTeam Bildverarbeitung GmbH
Development of a Workflow for Colored Ray Data by TechnoTeam Bildverarbeitung GmbH The importance of white LEDs has risen continuously over the past years. In many cases, disturbing color fringes appear on white LEDs with a blue chip and a yellow phosphor. To avoid this, different distribution of the blue and the yellow light has to be described for simulation. Therefore, colored ray files are necessary. Nicole Stubenrauch, Development Engineer at TechnoTeam Bildverarbeitung GmbH, explains a workflow and method for creating colored ray files. Read more »
LpR Article | Jun 20, 2016
Thermal Transient Testing of LEDs for More Reliable SSL Products by Mentor Graphics
Thermal Transient Testing of LEDs for More Reliable SSL Products by Mentor Graphics An LED device’s reliability, useful operating lifetime and luminous flux are basically determined by the junction temperature; therefore, so is the lifetime and reliability of the final SSL application. Thermal transient testing is now supported by new industrial laboratory testing standards published by JEDEC. Dr. Andras Poppe, Mechanical Analysis Division, MicReD, at Mentor Graphics will explain the corner stones of this standard and discuss application examples. This includes measurement of the RthJC, test-based thermal modeling of the LED package, hot lumens prediction, and monitoring of degradation of the thermal interfaces during life-time test, to name just a few. Read more »
LpR Article | Technologies | Jun 20, 2016
High Color-Rendering, Full-Visible-Spectrum LEDs by Soraa
High Color-Rendering, Full-Visible-Spectrum LEDs by Soraa The first wave of conventional white LEDs primarily focused on lumens per Watt. These LEDs were based on phosphor down-conversion using primary blue “pump” emission. Currently LEDs are catching up in regards to light quality using different approaches. Aurelien David, Senior Principal Scientist and Mike Krames, Chief Technology Officer at Soraa explain their technology approach of violet-pumped, full-visible-spectrum LEDs, and the interrelated challenges and advantages. Read more »
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