Category Archives: LED Manufacturing

Perovskite materials have shown great promise for use in next-generation solar cells, light-emitting devices (LEDs), sensors, and other applications, but their instability remains a critical limitation.

Researchers at UC Santa Cruz attacked this problem by focusing on perovskite nanocrystals, in which the instability problems are magnified by the large surface area of the particles relative to their volume. Atoms on the surface are vulnerable to reactions that can degrade the material, so molecules that bind to the surface–called surface ligands or capping ligands–are used both to stabilize perovskite nanocrystals and to control their properties.

In a paper published June 13 in Angewandte Chemie, the UCSC researchers reported the results of experiments using unique branched ligands to synthesize perovskite nanocrystals with greatly improved stability and uniform particle size.

“This new strategy to stabilize organometal-halide perovskites is an important step in the right direction,” said corresponding author Jin Zhang, professor of chemistry and biochemistry at UC Santa Cruz. “Our hope is that this could be used not only for perovskite nanocrystals but also for bulk materials and thin films used in applications such as photovoltaics.”

Zhang’s team tested the effects of different types of capping ligands on the stability of perovskite nanocrystals. Conventional perovskite nanocrystals capped with ligands consisting of long straight-chain amines show poor stability in solvents such as water and alcohol. Zhang’s lab identified unique branched molecules that proved much more effective as capping ligands.

According to Zhang, the branching structure of the ligands protects the surface of the nanocrystals by occupying more space than straight-chain molecules, creating a mechanical barrier through an effect known as steric hindrance. “The branching molecules are more cone-shaped, which increases steric hindrance and makes it harder for the solvent to access the surface of the nanocrystals,” he said.

The researchers were able to control the size of the nanocrystals by adjusting the amount of branched capping ligands used during synthesis. They could obtain uniform perovskite nanocrystals in sizes ranging from 2.5 to 100 nanometers, with high photoluminescence quantum yield, a measure of fluorescence that is critical to the performance of perovskites in a variety of applications.

Zhang’s lab is exploring the use of perovskite nanocrystals in sensors to detect specific chemicals. He is also working with UC Santa Cruz physicist Sue Carter on the use of perovskite thin films in photovoltaic cells for solar energy applications.

Almost two years after GTAT’s bankruptcy, the sapphire industry is still there. Its decor and characters have, of course, changed but the story is still unfolding. Survival strategies, emerging applications and niche markets, mergers and acquisitions. All the protagonists are contributing to altering the landscape, trying to identify new business opportunities to absorb the sapphire overcapacity. China is a major contributor to the story with new investments and emerging companies in this already saturated industry. What is the impact on the sapphire supply chain? What are the strategies to be adopted to succeed? What are the long-term perspectives?

Figure 1

Figure 1

In this tense economic environment, Yole Développement (Yole) and its partner CIOE are organizing a 1.5 day conference to learn more about the status of the sapphire industry. The event will provide an opportunity for all the participants to discuss the future of this industry and to find answers. Sapphire is now more affordable than ever and new capabilities have enabled the manufacturing of components for very diverse applications. The 2nd International Forum on Sapphire Market & Technologies is the place to be to understand today’s economic and technical challenges and build tomorrow’s industry.

The Yole & CIOE Forum will take place from September 6 to 7 in Shenzhen, China, alongside the 18th China International Optoelectronic Expo 2016. To find out more about this event, visit: Sapphire Forum Agenda – Sapphire Forum Registration.

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Figure 2

 The LED sector still has the highest demand for sapphire, but the expected volumes cannot sustain the one hundred or so sapphire producers currently competing in the industry.
Some sapphire companies are leaving the most commoditized markets and shifting their development strategies toward niche markets with higher added-value such as medical, industrial and military applications. Other business opportunities could materialize, including microLED arrays and other consumer applications.

Most sapphire companies are chasing any opportunity to survive and optimize their cost structure within a market which is currently characterized by a relentless price war. In Q1- 2016, the sapphire price plunged to its lowest ever level and most companies experienced a drastic decrease in revenue.

In this highly competitive market with significant economic constraints, Yole and CIOE are organizing the 2nd International Forum on Sapphire Market & Technologies (Shenzhen, China – September 6&7, 2016).

“The Sapphire Forum is an opportunity for the entire supply chain to come together to assess the current status of the industry, understand what lies ahead and determine the best strategies to make it through the crisis”, comments Dr. Eric Virey, Senior Technology & Market Analyst, Yole.

Today, SEMI announced that 19 new fabs and lines are forecasted to begin construction in 2016 and 2017, according to the latest update of the SEMI World Fab Forecast report. While semiconductor fab equipment spending is off to a slow start in 2016, it is expected to gain momentum through the end of the year. For 2016, 1.5 percent growth over 2015 is expected while 13 percent growth is forecast in 2017.

Fab equipment spending ─ including new, secondary, and in-house ─ was down 2 percent in 2015. However, activity in the 3D NAND, 10nm Logic, and Foundry segments is expected to push equipment spending up to US$36 billion in 2016, 1.5 percent over 2015, and to $40.7 billion in 2017, up 13 percent. Equipment will be purchased for existing fabs, lines that are being converted to leading-edge technology, as well as equipment going into new fabs and lines that began construction in the prior year.

Table 1 shows the regions where new fabs and lines are expected to be built in 2016 and 2017. These projects have a probability of 60 percent or higher, according to SEMI’s data. While some projects are already underway, others may be subject to delays or pushed into the following year. The SEMI World Fab Forecast report, published May 31, 2016, provides more details about the construction boom.

new fab lines

Breaking down the 19 projects by wafer size, 12 of the fabs and lines are for 300mm (12-inch), four for 200mm, and three LED fabs (150mm, 100mm, and 50mm). Not including LEDs, the potential installed capacity of all these fabs and lines is estimated at almost 210,000 wafer starts per month (in 300mm equivalents) for fabs beginning construction in 2016 and 330,000 wafer starts per month (in 300mm equivalents) for fabs beginning construction in 2017.

In addition to announced and planned new fabs and lines, SEMI’s World Fab Forecast provides information about existing fabs and lines with associated construction spending, e.g. when a cleanroom is converted to a larger wafer size or a different product type.

In addition, the transition to leading-edge technologies (as we can see in planar technologies, but also in 3D technologies) creates a reduction in installed capacity within an existing fab. To compensate for this reduction, more conversions of older fabs may take place, but also additional new fabs and lines may begin construction.

For insight into semiconductor manufacturing in 2016 and 2017 with details about capex for construction projects, fab equipping, technology levels, and products, visit the SEMI Fab Database webpage and order the SEMI World Fab Forecast Report. The report, in Excel format, tracks spending and capacities for over 1,100 facilities including over 60 future facilities, across industry segments from Analog, Power, Logic, MPU, Memory, and Foundry to MEMS and LEDs facilities.

Imagine a device that is selectively transparent to various wavelengths of light at one moment, and opaque to them the next, following a minute adjustment.

Such a gatekeeper would enable powerful and unique capabilities in a wide range of electronic, optical and other applications, including those that rely on transistors or other components that switch on and off.

In a May 20 paper in the journal Physical Review Letters, researchers in the University at Buffalo School of Engineering and Applied Sciences report a discovery that brings us one step closer to this imagined future.

A photograph (left) shows the experimental set-up used to confirm the existence of the Bloch wave resonance, which was first predicted theoretically. An illustration (right) shows the interior of the experimental device, called a hollow periodic waveguide, which consists of two corrugated metallic plates separated by a variable distance of about one inch, and the upper plate can slide with respect to the lower. When researchers shot microwaves between the plates through the air, they were able to control which wavelengths of microwaves were allowed through by varying the position of the upper plate. Credit: Lab of Victor Pogrebnyak/University at Buffalo

A photograph (left) shows the experimental set-up used to confirm the existence of the Bloch wave resonance, which was first predicted theoretically. An illustration (right) shows the interior of the experimental device, called a hollow periodic waveguide, which consists of two corrugated metallic plates separated by a variable distance of about one inch, and the upper plate can slide with respect to the lower. When researchers shot microwaves between the plates through the air, they were able to control which wavelengths of microwaves were allowed through by varying the position of the upper plate. Credit: Lab of Victor Pogrebnyak/University at Buffalo

The finding has to do with materials that are periodic, which means that they’re made up of parts or units that repeat. Crystals fall into this category, as do certain parts of the wings of butterflies, whose periodic structure helps give them color by reflecting specific colors of light.

Scientists have known since the early 20th century that periodic materials have special qualities when it comes to light. Such materials can reflect light, as butterfly wings do, and if you understand the internal structure of a periodic material, you can use an equation called Bragg’s law to determine which wavelengths will pass through the material, and which will be blocked due to reflection.

The new UB study shows that a completely periodic material structure is not needed for this kind of predictable reflection to take place.

Similar effects occur when you sandwich a non-periodic material between two boundary layers of material that have a periodic shape. This set-up will be transparent to certain wavelengths of light and opaque to others, and engineers can quickly alter which wavelengths are allowed through by simply moving one of the periodic boundaries.

Better yet, the effect not only applies to light waves, but rather to a broad range of wave phenomena that span the quantum to the continuum scale.

“We have shown that Bragg’s law is a special case of a more generalized phenomenon that was discovered in this study and named as a Bloch wave resonance,” said Victor A. Pogrebnyak, an adjunct associate professor of electrical engineering at UB. “This discovery opens up new opportunities in photonics, nanoelectronics, optics and acoustics and many other areas of science and technology that exploit band gap wave phenomena for practical use.”

“Electrons behave as waves that can also exhibit a Bloch resonance, which can be used as a powerful method to control currents in nanoelectronic circuits,” said Edward Furlani, Pogrebnyak’s co-author and a UB professor in the Departments of Chemical and Biological Engineering and Electrical Engineering.

A key advantage that Bloch wave resonance offers: It enables the blocking of a larger range of wavelengths simultaneously than previously known effects described by Bragg’s law.

Applications that could take advantage of this broader “band gap” range include white light lasers and a new type of fast-switching transistor.

The car is not a simple mode of transportation anymore. In addition to security and autonomous driving features, car manufacturers are considering more and more functionalities to propose vehicles as custom and fashion item.

During the last few years, electronic, optoelectronic, software and various digital technologies along with societal changes are increasingly pressuring the automotive players in transforming offerings and business models faster than ever before. Under this context, automotive OEM firms remain focused on core competencies and also develop new ones. Lighting technologies are part of them.
The lighting market for automotive applications should reach a 23.7% compound annual growth rate (CAGR) 2015-2121 reaching a US$27.7 billion market in 2021, announces Yole Développement (Yole) in its latest LED report entitled “Automotive Lighting: Technology, Industry and Market trends”. The increasing role of design and the introduction of new functionalities including ambient light, rear light, turn signal, parking & day ruing lights, fog light, low/high beam light and more are the reasons of this success. But what are the companies behind this impressive growth? What will be the impact on the supply chain? LED, OLED – which technologies are today able to answer to the market needs? The market research and strategy consulting offers today its vision of this industry.

With this new technology & market analysis, the “More than Moore” company, Yole investigates the attractive world of lighting solutions for automotive applications. The automotive lighting report from Yole analyzes the status of the market and its applications. It reviews the structure of the automotive lighting industry and details the market and technology trends. Under this new analysis, Yole’s experts present the main lighting technologies developed for automotive applications and propose valuable roadmaps until 2021. They cover the whole supply chain from devices to systems and give market insights between 2013 and 2021.

With the recent integration of LED technology, lighting has evolved from a basic, functional feature to a distinctive feature with high-value potential in automotive. Indeed, LED technology has given manufacturers the opportunity for strong differentiation via lighting design and additional functionalities. This is particularly true for exterior lighting, but it is also spreading to interior lighting. These changes are heavily impacting the supply chain, with new suppliers and a new value chain emerging.

In 2015, the automotive lighting market totaled nearly US$22.4 billion, up 5.4% from 2014. “This growth was driven by increased lighting system content per vehicle and a more favorable product mix driven by strong adoption of LED-based front lighting systems,” says Pars Mukish, Business Manager, LED, OLED and sapphire activities at Yole. Indeed, headlamp and DRL systems represented 43% and 28% of total 2015 revenue, respectively. Other lighting systems including rear combination light/center high-mounted signal light, interior light, and side turn-signal light comprised the remaining 29% of 2015 revenue. According to Yole’s analysts, the automotive lighting market will continue growing, reaching a market size of almost US$27.7 billion by 2021 – +23.7% compared to 2015, and driven by different growth areas:
• Short-term: increased LED technology penetration rate into different automotive lighting applications/systems, and increased lighting content per vehicle.
• Middle/long-term: potential integration of new lighting technologies like OLED and laser, development of AFLS and other security functions, and incredible developments employing lighting as a new design feature.

automotive lighting industry

“From a geographic point of view, Asia is the largest market for automotive lighting systems, reflecting the trends in term of vehicle production location but with higher share of revenue from Europe due to more favorable product mix in this area,” explains Pierric Boulay, Technology & Market Analyst at Yole. However European and Japanese companies dominate and supply together 81% of the market:
• Koito, Stanley and Ichikoh capture 40% of the revenue
• From an European side, Yole’s analysts announce 13-14% market share for each key European players: Magneti Marelli, Hella and Valeo.

Yole’s report presents all automotive lighting applications and the associated market revenue for the period 2013 – 2021, with details concerning drivers and challenges, integration status of different lighting technologies and systems, recent trends, and market size per application

Kateeva today announced that it has closed its Series E funding round with $88 million in new financing.

The Silicon Valley technology leader disrupted the flat panel display industry when it launched a breakthrough equipment solution to mass-produce flexible Organic Light Emitting Diodes (OLEDs). Flexible OLED technology gives limitless stretch to new product design innovation by liberating panel manufacturers from the constraints of glass substrates. It enables ultra-thin, feather-light displays that are bendable, roll-able, and even fold-able. Kateeva’s solution, known as the YIELDjet™ platform, leverages inkjet printing with novel innovations to perform critical steps in the OLED manufacturing process. Today, YIELDjet tools are helping to accelerate the adoption of OLED technology — a trend that’s taking the global display industry to exciting new heights.

The new Kateeva investors are: BOE, Cybernaut Venture, GP Capital Shanghai, Redview Capital, and TCL Capital, all located in China. They join existing investors that include: Samsung Venture Investment Corporation (SVIC), Sigma Partners, Spark Capital, Madrone Capital Partners, DBL Partners, New Science Ventures, and VEECO Instruments, Inc.

The company has raised $200 million since it was founded in 2008.

New Board seats will be filled by an executive from BOE, Redview Capital, and TCL Capital respectively.

The funds will accelerate new product development. The money will also help Kateeva expand manufacturing capacity at its Silicon Valley headquarters, where production systems are being built. In addition, the funds will strengthen Kateeva’s customer satisfaction infrastructure in Asia, and support continued R&D.

The round closes as demand for flexible OLED displays soars. This year, the market for plastic and flexible OLED displays will reach $2.1 billion, says Guillaume Chansin, Ph.D., Senior Technology Analyst at research firm IDTechEx. By 2020, it will surpass $18 billion. While mobile phones and wearables are currently the two main applications, Chansin expects that the technology will be found in tablets and automotive in the coming years.

The market trajectory is due to the confluence of two trends: first, voracious demand for flexible devices made possible by the enabling advantages of OLED technology; and second, the introduction of manufacturing tools like Kateeva’s YIELDjet platform that provided a pathway to cost-effective mass-production of flexible OLEDs for the first time.

Kateeva Chairman and CEO Alain Harrus, Ph.D. noted how OLED technology first transformed the viewing experience by giving spectacular color quality and brightness to rigid displays on mobile phones. “Now, it’s giving extraordinary new shape, lightness and thinness to those products and others that have yet to be invented,” he said. “Kateeva started enabling this “freedom from glass” display innovation in 2008 when our founders began pioneering a superior mass-production equipment solution for OLEDs. Today, Kateeva tools are positioned in top OLED manufacturing fabs. Our investors were stalwart partners along the way. We’re grateful for their support, and we welcome our new investors.”

Flexible OLED is the first major application for Kateeva’s YIELDjet platform, according to President and Co-Founder Conor Madigan, Ph.D. “Next up is OLED TV,” he said. “Having mastered the technical challenges of mass-producing Thin Film Encapsulation (TFE) — the layer that gives thinness and flexibility to the OLED device, we’re now applying YIELDjet technology to help display manufacturers mass-produce the OLED RGB layer, which enables OLED TVs. The new funds will accelerate new product development, and support ongoing R&D.”

Kateeva executives will be present at Display Week 2016. The premier international symposium for the display industry will be held May 22-27 at the Moscone Convention Center in San Francisco, Calif. President and Co-Founder Conor Madigan, Ph.D. will present on Kateeva’s technology on Monday, May 23. Chairman and CEO Alain Harrus, Ph.D. will speak at the Investors Conference on Tuesday, May 24.

Ultratech, Inc., a supplier of lithography, laser­ processing and inspection systems used to manufacture semiconductor devices and high­brightness LEDs (HB­ LEDs), as well as atomic layer deposition (ALD) systems, announced the formation of a research collaboration with Professor Thomas J. Webster, Ph.D. at Northeastern University, to study the use of nano-materials produced via ALD for medical applications. The initial research has focused on inhibiting bacterial growth and inflammation and promoting cell and tissue growth.

Dr. Thomas Webster, Chair and Professor of Chemical Engineering at Northeastern, said, “We are very excited to embark on this collaboration with Ultratech-CNT. While we are in the early stages of this study, the initial results of our work suggest that the materials and processes we are developing could have long-range impact in this field.”

Ultratech-CNT Senior Research Scientist Ritwik Bhatia, Ph.D., who has been working closely with Professor Webster, explained, “This type of work is a marked departure from the traditional applications and uses for ALD and dramatically opens up a new field where material science and life sciences intersect. I am extremely pleased to be part of this research program and excited by the potential benefits for healthy surgical outcomes that this research represents.”

Arthur W. Zafiropoulo, Ultratech’s Chairman and Chief Executive Officer, said, “At Ultratech, we have long maintained and understood that material science would play a key role in moving many emerging technological fields forward. We also feel that it can serve a much larger role, namely in improving the quality of life. In linking the expertise of Prof. Webster and his research group with Ultratech-CNT’s ALD group, we believe we are taking steps to solidly and efficiently pursue our scientific and commercial goals.”

Standard solutions and devices are compared to a 60 V MOSFET with monolithic Schottky diode as evaluated in SMPS and motor control environments.

BY FILIPPO SCRIMIZZI and FILADELFO FUSILLO, STMicroelectronics, Stradale Primosole 50, Catania, Italy

On synchronous rectification and in bridge configuration, RDSon and Qg are not the only requirements for power MOSFETs. In fact, the dynamic behavior of intrinsic body-drain diode also plays an important role in the overall MOSFET performances. The forward voltage drop (VF,diode) of a body-drain diode impacts the device losses during freewheeling periods (when the device is in off-state and the current flows from source to drain through the intrinsic diode); the reverse recovery charge (Qrr) affects not only the device losses during the reverse recovery process but also the switching behavior, as the voltage spike across the MOSFET increases with Qrr. So, low VFD and Qrr diodes, like Schottky, can improve overall device performance, especially when mounted in bridge topologies or used as synchronous rectifiers—especially at high switching frequency and for long diode conduction times. In this article, we compare standard solutions and devices to a 60 V MOSFET with monolithic Schottky diode as evaluated in SMPS and motor control environments.

Intrinsic MOSFET body-drain diode and Schottky features

In FIGURE 1, the typical symbol for an N-channel Power MOSFET is depicted. The intrinsic body-drain diode is formed by the p-body and n–drift regions and is shown in parallel to the MOSFET channel.

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Once a Power MOSFET is selected, the integral body diode is fixed by silicon characteristic and device design. As the intrinsic body diode is paralleled to the device channel, it is important to analyze its static and dynamic behavior, especially in applications where the body diode conducts. So, maximum blocking voltage and forward current have to be considered in reverse and forward bias, while, when the diode turns-off after conducting, it is important to investigate the reverse recovery process (FIGURE 2). When the diode goes from forward to reverse bias, the current doesn’t reduce to zero immediately, as the charge stored during on-state has to be removed. So, at t = t0, the diode commutation process starts, and the current reduces with a constant and slope (-a), fixed only by the external inductances and the supply voltage. The diode is forward biased until t1, while from t1 to t2, the voltage drop across the diode increases, reaching the supply voltage with the maximum reverse current at t=t2. The time interval (t3-t0) is defined as reverse recovery time (trr) while the area between negative current and zero line is the reverse recovery charge (Qrr).The current slope during tB is linked mainly to device design and silicon characteristics.

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The classification of soft and snap recovery is based on the softness factor: Screen Shot 2016-05-11 at 12.09.58 PMthis parameter can be important in many applications. The higher the softness factor, the softer the recovery. In fact, if tB region is very short, the effect of quick current change with the circuit intrinsic inductances can produce undesired voltage overshoot and ringing. This voltage spike could exceed the device breakdown voltage: moreover, EMI performances worsen. As shown in Fig. 2, during diode recovery, high currents and reverse voltage can produce instantaneous power dissipation, reducing the system efficiency. Moreover, in bridge topologies, the maximum reverse recovery current of a Low Side device adds to the High Side current, increasing its power dissipation up to maximum ratings. In switching applications, like bridge topologies, buck converters, or synchronous rectification, body diodes are used as freewheeling elements. In these cases, reverse recovery charge (Qrr) reduction can help maximize system efficiency and limit possible voltage spike and switching noise at turn-off. One strategy to reach this target to integrate a Schottky diode in the MOSFET structure. A Schottky diode is realized by an electrical contact between a thin film of metal and a semiconductor region. As the current is mainly due to majority carriers, Schottky diode has lower stored charge, and consequently, it can be switched from forward to reverse bias faster than a silicon device. An additional advantage is its lower forward voltage drop (≈0.3 V) than Si diodes, meaning that a Schottky diode has lower losses during the on state.

Embedding the Schottky diode in a 60V power MOSFET is the right device choice when Qrr and VF,diode have to be optimized to enhance the overall system performance. In FIGURE 3, the main electrical parameters of standard and integrated Schottky devices (same BVDSS and die size) are reported.

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Benefits of Mono Schottky in a power management environment

In a synchronous buck converter (FIGURE 4), a power MOSFET with integrated Schottky diode can be mounted as a Low Side device (S2) to enhance the overall converter performance.

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In fact, Low Side body diode conduction losses (Pdiode,cond) and reverse recovery losses (PQrr) are strictly related to the diode forward voltage drop (VF,diode) and its reverse recovery charge (Qrr):

Screen Shot 2016-05-11 at 12.09.20 PM

As shown in (1) and (2), these losses increase with the switching frequency, the converter input voltage, and the output current. Moreover, the dead time, when both FETs are off and the current flows in the Low Side body diode, seriously affects the diode conduction losses: with long dead times, a low diode forward voltage drop helps to minimize its conduction losses, therefore increasing the efficiency. In FIGURE 5, the efficiency in a 60W, 48V – 12V, 250 kHz synchronous buck converter is depicted.

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Now, considering isolated power converters’ environment, when the output power increases and the dead time values are high, the right secondary side synchronous rectifier should have not only RDSon as low as possible to reduce conduction losses, but also optimized body diode behavior (in terms of Qrr and VF,diode) in order to reduce diode losses (as reported in (1) and (2)) and to minimize possible voltage spikes during turn-off transient. The 60V standard MOSFET and one with Schottky integrated devices are compared in a 500W digital power supply, formed by two power stages: power factor corrector and an LLC with synchronous rectification. The maximum output current is 42 A, while the switching frequency at full load is 80 kHz, and the dead time is 1μs. The efficiency curves are compared in FIGURE 6.

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In both topologies, the 60 V plus Schottky device shows higher efficiency in the entire current range, an improvement in overall system performance.

Switching behavior improvement in bridge topologies

In bridge topologies, reverse recovery process occurs at the end of the freewheeling period of the Low Side device (Q2 in FIGURE 7), before the High Side (Q1 in Fig. 7) starts conducting. The resulting recovery current adds to the High Side current (as previously explained). Together with the extra-current on the High Side device, the Low Side reverse recovery and its commutation from Vds ≈ 0 V to Vdc can produce spurious bouncing on the Low Side gate- source voltage, due to induced charging of Low Side Ciss (input capacitance) via Crss (Miller capacitance).

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As a consequence, the induced voltage on Q2 gate could turn-on the device, worsening system robustness and efficiency. A Low Side device, in bridge configuration, should have soft commutation, without dangerous voltage spikes and high frequency ringing across drain and source. This switching behavior can be achieved using power MOSFETs with integrated Schottky diode as Low Side devices. In fact, the lower reverse recovery charge (Qrr) has a direct impact on the overshoot value. In fact, the higher the Qrr, the higher the overshoot. Lower values for Vds overshoot and ringing reduce the spurious voltage bouncing on the Low Side gate, limiting the potential risk for a shoot-through event. Furthermore, soft recovery enhances overall EMI performances, as the switching noise is reduced. In FIGURE 8 are shown the High Side turn-on waveforms for standard and embedded Schottky devices; purple trace (left graph) and green trace (right graph) are Low Side gate-source voltages. The device with Schottky diode shows a strong reduction of Low Side spurious bouncing.

Screen Shot 2016-05-11 at 12.09.47 PM

Summary

In many applications (synchronous rectification for indus- trial and telecom SMPS, DC-AC inverter, motor drives), choosing the right MOSFET means not only considering RDSon and Qg but also evaluating the static and dynamic behavior of the intrinsic body-drain diode. A 60V “F7” power MOSFET with integrated Schottky diode ensures optimized performances in efficiency and commutation when a soft reverse recovery with low Qrr is required. Furthermore, the low VF,diode value achieves higher efficiency when long freewheeling periods or dead-times are present in the application.

References

1. “Fundamental of Power Semiconductor Devices”, B.J.Baliga – 2008, Springer Science

Dow Corning will present an exclusive glimpse of upcoming products and technologies at LIGHTFAIR International 2016 (Booth #3657), and showcase new advances in LED lamp and luminaire lighting that its broad commercial portfolio of cutting-edge optical silicone solutions are enabling worldwide.

“Three years ago, Dow Corning’s optical silicones technology sparked a surge of breakthrough innovations in LED lighting designs, and the demand for these uniquely advanced materials has only grown as the industry seeks to maintain the momentum they have helped build,” said Hugo da Silva, global industry director for LED lighting at Dow Corning. “Dow Corning is as committed as ever to working closely with customers to expand on their early successes, and formulate new optical silicone solutions to help them usher in the next-generation of LED illumination.”

Dow Corning will offer an early glimpse at LIGHTFAIR 2016 of at least one of those upcoming optical silicone solutions – Dow Corning MS-4002 Moldable Silicone. Planned for launch later this year, this high-performing material signals the latest advance in the company’s award-winning Moldable Silicone portfolio. Currently in development and testing, MS-4002 Moldable Silicone aims to offer the optimum balance of material toughness for reaching high IP and IK ratings, high light transmittance rate and smooth surface feel for secondary optics in LED lamp and luminaire applications for both indoor and outdoor.

As the global leader in silicone innovation and technology, Dow Corning is changing the game for LED design, and the company will show exactly how during LIGHTFAIR 2016. The booth will feature the company’s broad and growing range of proven solutions at three corner kiosks, focusing on:

  • Dow Corning Moldable Silicones, where visitors can explore how these materials are delivering proven solutions for enhancing the optical quality, efficiency and reliability of lamp and luminaire designs
  • Protection & Assembly Solutions, where customer products illustrate how Dow Corning’s innovative silicone protection, assembly and optical solutions have helped develop products with longer life cycles and greater efficiency in outdoor/architectural, interior/specialty, display and automotive lighting applications
  • Silicone-Enabled Designs demonstrating new ways to shape, direct and diffuse light more efficiently with Dow Corning Optical Silicones. Visitors can also explore how silicone materials have expanded innovative design possibilities as LumenFlow Corp. takes them step by step through the LED design ideas process

In addition to offering an exclusive sneak peek at upcoming technologies, Dow Corning Lighting experts will be on hand to discuss the unique design flexibilities, proven reliability and simpler processability enabled by Dow Corning’s optical silicones. A market leader in materials, expertise and collaborative innovation for LED lighting concepts, Dow Corning offers solutions that span the entire LED value chain, adding reliability and efficiency for sealing, protecting, adhering, cooling and shaping light across all lighting applications.

LIGHTFAIR International is the world’s largest annual architectural and commercial lighting trade show and conference. Held at San Diego’s Convention Center from April 26-28, this year’s edition is expected to attract over 28,000 design, lighting, architectural, design, engineering, energy, facility and industry professionals from around the world to set future trends for lighting, design and technology innovation.

LED Taiwan, the most influential LED exhibition in Taiwan, is organized by SEMI and the Taiwan External Trade Development Council (TAITRA). Opening at TWTC Nangang Exhibition Hall in Taipei on April 13-16, the four-day event features theme pavilions, industry forums, TechSTAGE and academic paper presentations. The Taiwan International Lighting Show (TiLS) is co-located. With 748 booths and 238 exhibitors demonstrating the local LED supply chains’ R&D capabilities, LED Taiwan is expected to attract over 16,000 visitors from Taiwan and internationally.

Research firm Strategies Unlimited estimates that the global LED packaging market had US$15.6 billion revenue in 2014. The market is expected to grow to US$22 billion by 2019, 45 percent from lighting applications. However, as the price of white LEDs continues to fall, new applications are regarded as the key to higher earnings. Prospects of niche-market applications like IR LED and UV LED look good, while automotive LED lights are becoming another important market with greater demand for high-power chips.

Five theme pavilions to fully demonstrate a complete LED industry chain

To satisfy the market’s demand for LED in an era of IoT, LED Taiwan 2016 will add three new pavilions — LED Components, Smart Lighting Technology, and Power Device — to the two existing pavilions High-Brightness LED and Sapphire. Leading players in the areas of LED equipment, materials, components and packaging ─ like Aurora Optoelectronics, Cree, Epileds, GlobalWafers, Han’s Laser, Lextar, an alliance of sapphire processing companies organized by the Metal Industries Research & Development Centre, Rapitech, Rubicon and Wei Min Industrial ─ will all showcase their products in the exhibition to help local and foreign visitors understand the structure, manufacturing processes and technologies of Taiwan’s LED industry.

Event to feature the results of innovation in five areas

To enable innovation and bring more energy to the local LED industry, TechSTAGE will be held as part of this year’s LED Taiwan event, showcasing Taiwan’s LED R&D capability in the areas of LED

Manufacturing Equipment & Materials, Power Device Technology, Sapphire Processing Technology & Application, LED Advanced Technologies, and Smart Lighting & Automobile Lighting.

Seeking more possibilities with innovative materials and power devices

As awareness about energy conservation increases around the world and the market seeks better profits and opportunities, more companies are investing in power device R&D and production. This has prompted LED Taiwan to focus on the hot topic of power devices this year, and in addition to a special pavilion for the segment, the event will also organize a forum for vendors to discuss and understand trends and development concerning this technology.

International forums to explore key issues in the industry

As the LED market is gradually maturing, companies in the industry are aggressively seeking new applications and “blue ocean” strategies. In addition to visible LED applications in back-lit display, mobile phones, lighting equipment and cars, more companies have invested in the development and production of invisible LEDs. While demand continues to diversify with a focus on custom-made applications, the ability to find new opportunities in this trend, improving competitiveness and innovation, will be the key to future success. The LED Taiwan 2016 Executive Summit will discuss future trends by exploring innovation, LED lighting/non-lighting opportunities, current challenges and strategies in the market. The IR and UV Summit will focus on IR and UV LED applications in wearable devices, medical appliances and measuring equipment in a bid to help participants get a quick grasp of latest trends around the world.

Integration of resources helps boost local LED industry’s global presence

LED Taiwan is made possible with the collaboration and resources from influential organizations in the industry, including SEMI, TAITRA, the Taiwan Lighting Fixture Export Association and the Taiwan Optoelectronic Semiconductor Industry Association. Each year, foreign buyers and leading manufacturers are invited to the exposition where various business matching events, VIP luncheons and banquet meetings are arranged to help Taiwan vendors expand connections and secure business opportunities by interacting with the elite members of foreign industrial and academic circles.

“SEMI has many connections and resources in the area of LED manufacturing, and by working with the Taiwan Lighting Fixture Export Association and TAITRA, we are able to organize LED Taiwan and TiLS at the same time, ” said Terry Tsao, president of SEMI Taiwan. “In addition to showing the world the robust ecosystem of Taiwan’s LED industry and attracting more foreign buyers, we also hope that innovative technologies and academic papers announced in the forums will help integrate industrial and academic resources. We want to create more opportunities for the LED industry and make Taiwan’s outstanding R&D capabilities visible to the world.”

LED Taiwan is the most influential LED exposition in Taiwan, showcasing LED production equipment & materials, epi wafers, crystals, packaging, modules, etc., as well as related technologies and manufacturing solutions. The Taiwan International Lighting Show is co-located at LED Taiwan as a multi-purpose event facilitating technology exchanges and procurement in the areas of LED and lighting. LED Taiwan was inaugurated in 2010, and in 2015, the event attracted buyers from over 68 countries and created more than US$13 million of business.

For more information on LED Taiwan, please visit: www.ledtaiwan.org/en/