The Kynix Blog - General electronic semiconductor

Written by Rob MathesonAn exotic material called gallium nitride (GaN) is poised to become the next semiconductor for power electronics, enabling much higher efficiency than silicon.In 2013, the Department of Energy (DOE) dedicated approximately half of a $140 million research institute for power electronics to GaN research, citing its potential to reduce worldwide energy consumption. Now MIT spinout Cambridge Electronics Inc. (CEI) has announced a line of GaN transistors and power electronic circuits that promise to cut energy usage in data centers, electric cars, and consumer devices by 10 to 20 percent worldwide by 2025.Power electronics is a ubiquitous technology used to convert electricity to higher or lower voltages and different currents—such as in a laptop's power adapter, or in electric substations that convert voltages and distribute electricity to consumers. Many of these power-electronics systems rely on silicon transistors that switch on and off to regulate voltage but, due to speed and resistance constraints, waste energy as heat.CEI's GaN transistors have at least one-tenth the resistance of such silicon-based transistors, according to the company. This allows for much higher energy-efficiency, and orders-of-magnitude faster switching frequency—meaning power-electronics systems with these components can be made much smaller. CEI is using its transistors to enable power electronics that will make data centers less energy-intensive, electric cars cheaper and more powerful, and laptop power adapters one- third the size—or even small enough to fit inside the computer itself."This is a once-in-a-lifetime opportunity to change electronics and to really make an impact on how energy is used in the world," says CEI co-founder Tomás Palacios, an MIT associate professor of electrical engineering and computer science who co-invented the technology.Other co-founders and co-inventors are Anantha Chandrakasan, the Joseph F. and Nancy P. Keithley Professor in Electrical Engineering, now chair of CEI's technical advisory board; alumnus Bin Lu SM '07, PhD '13, CEI's vice president for device development; Ling Xia PhD'12, CEI's director of operations; Mohamed Azize, CEI's director of epitaxy; and Omair Saadat PhD '14, CEI's director of product reliability.Making GaN feasibleWhile GaN transistors have several benefits over silicon, safety drawbacks and expensive manufacturing methods have largely kept them off the market. But Palacios, Lu, Saadat, and other MIT researchers managed to overcome these issues through design innovations made in the late 2000s.Power transistors are designed to flow high currents when on, and to block high voltages when off. Should the circuit break or fail, the transistors must default to the "off" position to cut the current to avoid short circuits and other issues—an important feature of silicon power transistors.But GaN transistors are typically "normally on"—meaning, by default, they'll always allow a flow of current, which has historically been difficult to correct. Using resources in MIT's Microsystems Technology Laboratory, the researchers—supported by Department of Defense and DOE grants—developed GaN transistors that were "normally off" by modifying the structure of the material.To make traditional GaN transistors, scientists grow a thin layer of GaN on top of a substrate. The MIT researchers layered different materials with disparate compositions in their GaN transistors. Finding the precise mix allowed a new kind of GaN transistors that go to the off position by default."We always talk about GaN as gallium and nitrogen, but you can modify the basic GaN material, add impurities and other elements, to change its properties," Palacios says.But GaN and other nonsilicon semiconductors are also manufactured in special processes, which are expensive. To drop costs, the MIT researchers—at the Institute and, later, with the company—developed new fabrication technologies, or "process recipes," Lu says. This involved, among other things, switching out gold metals used in manufacturing GaN devices for metals that were compatible with silicon fabrication, and developing ways to deposit GaN on large wafers used by silicon foundries."Basically, we are fabricating our advanced GaN transistors and circuits in conventional silicon foundries, at the cost of silicon. The cost is the same, but the performance of the new devices is 100 times better," Lu says.Major applicationsCEI is currently using its advanced transistors to develop laptop power adaptors that are approximately 1.5 cubic inches in diameter—the smallest ever made.Among the other feasible applications for the transistors, Palacios says, is better power electronics for data centers run by Google, Amazon, Facebook, and other companies, to power the cloud.Currently, these data centers eat up about 2 percent of electricity in the United States. But GaN-based power electronics, Palacios says, could save a very significant fraction of that.Another major future application, Palacios adds, will be replacing the silicon-based power electronics in electric cars. These are in the chargers that charge the battery, and the inverters that convert the battery power to drive the electric motors. The silicon transistors used today have a constrained power capability that limits how much power the car can handle. This is one of the main reasons why there are few large electric vehicles.GaN-based power electronics, on the other hand, could boost power output for electric cars, while making them more energy-efficient and lighter—and, therefore, cheaper and capable of driving longer distances. "Electric vehicles are popular, but still a niche product. GaN power electronics will be key to make them mainstream," Palacios says.Innovative ideasIn launching CEI, the MIT founders turned to the Institute's entrepreneurial programs, which contributed to the startup's progress. "MIT's innovation and entrepreneurial ecosystem has been key to get things moving and to the point where we are now," Palacios says.Palacios first earned a grant from the Deshpande Center for Technological Innovation to launch CEI. Afterward, he took his idea for GaN-based power electronics to Innovation Teams (i-Teams), which brings together MIT students from across disciplines to evaluate the commercial feasibility of new technologies. That program, he says, showed him the huge market pull for GaN power electronics, and helped CEI settle on its first products."Many times, it's the other way around: You come out with an amazing technology looking for an application. In this case, thanks to i-Teams, we found there were many applications looking for this technology," Palacios says.For Lu, a key element for growing CEI was auditing Start6, a workshop hosted by the Department of Electrical Engineering and Computer Science, where entrepreneurial engineering students are guided through the startup process with group discussions and talks from seasoned entrepreneurs. Among other things, Lu gained perspective on dividing equity, funding, building a team, and other early startup challenges."It's a great class for a student who has an idea, but doesn't know exactly what's going on in business," Lu says. "It's kind of an overview of what the process is going to be like, so when you start your own company you are ready."   

A Semiconductor is an element which is intermediate of conductor and an insulator. Semi-conductor is kind of material that contains electrical conductivity value between a conductor and an insulator such as copper or glass. Semi-conductors are the base of modern electronics. Semi-conductors are responsible for the computer Technology and its formation, which began in the mid of 20th century and still continuing.Semiconductor devices or electronic circuit components made from a material that is neither a good conductor nor a good insulator (called semiconductor). These devices have found wide applications because of their reliability, compactness, and very low cost. Semi-conductor systems or components are actually electronic components that take advantage of the electronic properties of the semi-conductor materials such as germanium, silicon and gallium arsenide. With the invention of the semiconductor devices have replaced most of the most of the vacuum tube applications. A semiconductor device is manufactured as either single discrete device or as integrated circuits. The integrated circuits include a few number to few million devices interconnected to a single semiconductor substrate. The cause why the semiconductor equipments are used in developing most devices is that the behavior of a semiconductor can easily be controlled by adding impurities which is or else called as doping. Transmission in a semi conductor occurs by free electrons which on the whole are called as the charge carriers.Semiconductors have massive impact on our society. Semiconductors mostly presents at the heart of microprocessor chips as well as transistors. Anything that's automated or uses radio waves depends on semiconductors. Today's mostly semiconductor chips and transistors are created with silicon. We may have heard words like "Silicon Valley" and the "silicon economy," and that's why -- silicon is the heart of any electronic device.A list of Semiconductor Components and devices includes Gunn diode, Avalanche diode, Light-emitting diode, PIN diode, IMPATT diode, DIAC, Schottky diode, Diode, Laser diode, Photocell, Tunnel diode, Solar cell, VCSEL, VECSEL and Zener diode are two terminal devices. The three terminal devices includes Darlington transistor, Bipolar transistor, Field effect transistor, IGBT, GTO, (Switched Gate Commuted Thyristor),SCR (Silicon Controlled Rectifier), SGCT, Thyristor, TRIAC, Unijunction transistor. The four terminal devices contains Hall Effect sensor (magnetic field sensor), Microprocessor, Multi-terminal devices comprises of Charge-coupled device (CCD), Read-only memory (ROM), Random Access Memory (RAM), and the list goes on.Written by  David John

LCD stands for “liquid crystal display” and technically, both LED and LCD TVs are liquid crystal displays. The basic technology is the same in that both television types have two layers of polarized glass through which the liquid crystals both block and pass light. So really, LED TVs are a subset of LCD TVs.LED, which stands for “light emitting diodes,” differs from general LCD TVs in that LCDs use fluorescent lights while LEDs use those light emitting diodes. Also, the placement of the lights on an LED TV can differ. The fluorescent lights in an LCD TV are always behind the screen. On an LED TV, the light emitting diodes can be placed either behind the screen or around its edges. The difference in lights and in lighting placement has generally meant that LED TVs can be thinner than LCDs, although this is starting to change. It has also meant that LED TVs run with greater energy efficiency and can provide a clearer, better picture than the general LCD TVs.Source: BY HOWSTUFFWORKS.COM CONTRIBUTORS   

Whether you are working on the latest device for your company or you are trying to find a replacement part for an old electronic device, finding a company to help you search for the parts you need is only half the battle. One of the difficult things to know is if your order contains exactly what you are expecting to get.  This is why knowing what kind of quality inspection process your parts supplier uses is becoming more important.These days the electronic components distributors and wholesalers are facing a difficult task especially with more and more fake, counterfeit and sub standard components making their way onto the market, this problem seem to be growing every year.The distributors and wholesalers that you use to supply your part requirements should have a tough inspection process in place to ensure you will be receiving the best quality product possible.A good quality inspection process would include several different factors including certified quality control inspectors, daily audits by lead inspectors to ensure a consistent, superior level of product inspection, a rigorous visual inspection and component tests to determine that products conform to manufacturers specifications and a quarantine and rejection process to ensure sub-standard products do not find their way into the market or into your projects.Counterfeiters today are becoming more sophisticated and making their products more difficult to recognize. A good sign that your supplier is helping the fight against counterfeit and sub-standard products is if they are a member of Independent Distributors of Electronics Association (IDEA) and use the IDEA-STD-1010-A standard. This standard was developed in 2006 by its members and is used to help educate and continue to educate its members by keeping their quality inspection processes up to date to help fight against the increase of poor or counterfeit parts. One company who is a member of IDEA and who has been in the Electronic parts and component distribution business since 1972 is Electrospec based in Dover, New Jersey.Electrospec’s quality inspection process uses the IDEA-STD-1010-A standard as a basis for their extensive quality control. They are a member of ERAI (Electronic Resellers Association, Inc.) and approved ISO 9001:2000 Certification by SGS Systems & Services Certification with their ISO quality system incorporating the relevant standards of ANSI/ESDS20.20-1999 that are applicable to an electronic components distributor.Electrospec also does all the component sourcing for PartsSearcher.com which has an extensive online parts catalogue and an online request for quote online submission form.The bottom line is don’t be afraid to ask your supplier about their quality inspection process, if it’s good enough they will not only be happy to talk to you about it they will want to boast about how good it is.