Category Archives: FPDs and TFTs

In recent years, TFT-LCD technology has dominated the display panel market, everything from small, medium and large screens, to the point where all other rival display technologies such as e-paper, PDP, and CRT have steadily been losing their positioning. Amidst this trend, only the AMOLED panel market, led by Samsung Display, emerged as the most formidable competitor to TFT-LCD, showing a steady and fast growth.

Several fast-moving panel manufacturers see the potential in the AMOLED panel business and are planning to enter this market in the near future. Despite such interest in the market, only a handful of companies, including Samsung Display, LG Display, and Sony, are successfully producing on a large scale.

This state can be attributed to several obstacles. The first is the higher degree of technical difficulty in producing AMOLED panels compared to TFT-LCDs. Even with successful AMOLED production, toppling TFT-LCDs from their current dominant position of performance and cost advantageousness is a daunting task. In addition, the market is trending toward bigger screens with higher resolutions, which make penetrating the competitive AMOLED market even harder because the late comers have to develop both standard and cutting-edge technologies at the same time.

As a result, AMOLED manufacturers will strive to penetrate the market with diverse strategic planning this year in order to overcome the various technological and competitive obstacles. More specifically, the majority of manufacturers already producing TFT-LCD panels are busy reckoning gains and losses of making AMOLED panels alongside and how they will be able to maximize profits with minimized investment. 

The paradigm shift of the small and medium-sized OLED manufacturing process and substrate process deserves attention in 2013. In the small and medium-sized OLED manufacturing process, open mask-applied WOLED structure is being widely attempted, since it is easy to implement even though the performance is inferior when compared to high precision deposition methods, such as traditional fine metal mask evaporation-applied RGB light-emitting structure, LITI, and ink jet printing. There is also an attempt to produce unbreakable AMOLED panels with a goal to replace flatbed glass used for substrate and encapsulation layer with plastic and thin-film coating, respectively. If realized, the emergence of such an unbreakable AMOLED screen should stand as a groundbreaking innovation for the display panel market as a whole along with the related technology applications sector.

Displaybank has researched the issues and strategies for each and every player in the AMOLED market and published its timely report “AMOLED Panel Makers’ Business Strategy and Market Forecast” in order for the companies to safely navigate through obstacles. The report should offer firms insight into penetrating the competitive AMOLED panel market with helpful and individualized strategies.

Ditch the 3D glasses. Thanks to a simple plastic filter, mobile device users can now view unprecedented, distortion-free, brilliant 3D content with the naked eye. This latest innovation from TP and IMRE is the first ever glasses-free 3D accessory that can display content in both portrait and landscape mode, and measures less than 0.1 mm in thickness.

“The filter is essentially a piece of plastic film with about half a million perfectly shaped lenses engineered onto its surface using IMRE’s proprietary nanoimprinting technology,” said Dr. Jaslyn Law, the IMRE scientist who worked with TP on the nanoimprinting R&D since 2010 to enhance the film’s smoothness, clarity and transparency compared to other films in the market.

To complement the filter, the team developed applications for two software platforms, Apple iOS and Android, which allow users to play 3D content through its filter, in both landscape and portrait formats. The applications also allow 2D pictures taken using mobile devices to be converted into 3D. The team will be releasing a software development kit that enables game developers to convert their existing games into 3D versions.

The team is also exploring using the same technology for security access tokens to decode PIN numbers sent online as an inexpensive and portable alternative to rival bulkier and more expensive battery-operated security tokens, similar to those used by Singapore banks today.

“The team’s expertise in both hardware and software development in 3D technology has enabled high quality 3D to be readily available to consumers,” said Frank Chan, the TP scientist who led the overall NRF-funded project. “We have taken age old lenticular lens technology that has been around for the last hundred years, modernized it and patented it using nanotechnology.”

Lenticular lens technology creates a transparent film that retains the brilliance of 3D visuals and effects, which does away with the need for stronger back lighting and saves on battery consumption in mobile devices.

“The successful development of this product is indeed testimony that we have been able to bridge the gap between R&D and commercialisation in the area of 3D interactive digital media (IDM), aided by the NRF Translational R&D Grant and gap funding from A*STAR,” said Lay-Tan Siok Lie, Deputy Principal of TP.

The two-year project was initially funded under a National Research Foundation (NRF) Translational R&D Grant in Dec 2010 to look at optimizing the control of the nanostructures and integrating its effects with the complementary software applications. The team has since shifted its focus towards commercialization with support from Exploit Technologies  Pte  Ltd  (ETPL),  A*STAR’s  technology transfer  arm and a one-stop resource that brings together home-grown technology, funding, collaboration and networks to assist A*STAR spin-offs and start-ups.

“Our breakthrough is a game-changing piece of plastic that simply fits onto current smartphones or tablets to give users breathtaking 3D graphics on their smart devices. This removable plastic also opens up a multitude of opportunities for anyone wanting to create affordable premium 3D content and games for quick adoption to existing portable devices easily,” said Nanoveu Pte Ltd Founder and CEO, Alfred Chong.

The start-up is licensing the technology exclusively from ETPL and TP, and is currently securing the interest of local and overseas customers and investors.

“The success of this project is typical of what IMRE aims to do – innovate and turn science into an exciting business opportunity. I’m glad this has given us products that make life just a little bit more fun,” said Andy Hor, Executive Director of IMRE.

The new Galaxy S4 from Samsung Electronics joins a growing trend of premium smartphones featuring enhanced active-matrix organic light-emitting diode (AMOLED) panels, spurring the market for these high-quality displays to more than double by 2017.

AMOLED display shipments for mobile handset applications are expected to grow to 447.7 million units in 2017, up from 195.1 million units in 2013, according to insights from the IHS iSuppli Emerging Displays Service at information and analytics provider HIS. Within the mobile handset display market, the market share for AMOLED displays is forecast to grow from 7.9% in 2013 to 15.2 percent in 2017, as presented in the figure below. AMOLED’s market share for 4-inch or larger handset displays employed in smartphones is set to increase to 24.4% in 2017, up from 23.0% in 2013.

AMOLED display shipments

“Because of their use in marquee products like the Galaxy S4, high-quality AMOLEDs are growing in popularity and gaining share at the expense of liquid crystal display (LCD) screens,” said Vinita Jakhanwal, director for mobile & emerging displays and technology at IHS. “These attractive AMOLEDs are part of a growing trend of large-sized, high-resolution displays used in mobile devices. With the S4 representing the first time that a full high-definition (HD) AMOLED has been used in mobile handsets, Samsung continues to raise the profile of this display technology.”

AMOLED on display in the S4

For its new premium smartphone, Samsung Display—the AMOLED display supplier for Samsung Electronics—increased the AMOLED pixel format to 1920 by 1080 Full High Definition (Full HD), up from 1280 x 720 WXGA present in the Galaxy S III. Part of Samsung’s popular Galaxy line, the S4 joins several high-end smartphone models from other manufacturers also featuring 1920 by 1080 resolution but distinguished by an important difference. The other handsets use thin-film transistor LCD (TFT-LCD) displays, while the Galaxy S4 is the first Full HD smartphone utilizing an AMOLED display.

Among the handsets with 1920 by 1080 TFT-LCD panels are the 4.8-inch HTC One, the 5.0-inch Sony Xperia Z, the 5.0-inch ZTE Grand S, the 5.0-inch OPPO Find, the 5.5-inch LG Optimus G Pro and the 5.5-inch Lenovo Ideaphone K900.

Samsung tackles technical issues

The high-resolution mobile handset display market is currently dominated by Low-Temperature Polysilicon (LTPS) TFT-LCDs, which accounts for the entire Full HD mobile handset display market.

Reaching the high-resolution point with true pixel densities greater than 300 pixels per inch (ppi) has been a challenge for AMOLED displays, as it is difficult to achieve dense pixel arrangements using the conventional Fine Metal Mask process while still securing enough display brightness and not compromising power consumption.

Samsung Display, however, was able to enhance AMOLED display performance by implementing two new technologies in addition to its existing Fine Metal Mask process. The maker succeeded in increasing the lighting area in AMOLED panels with its new structure of Pentile matrix, and it used phosphorescent material for the green subpixels, allowing better light management and lower energy consumption.

As a result, the AMOLED display was able to achieve a denser pixel arrangement, boosting its pixel density to greater than 400 ppi and resulting in 1920 x 1080 Full HD display in the Galaxy S4. This compares to 1280 x 720 WXGA in the Galaxy S III, 800 x 480 WVGA in the Galaxy S2 and 1280 x 800 WXGA in the Galaxy Note. The higher pixel density provides sharper and more defined images, while being able to display more content on a smaller display area.

Samsung also implemented the Floating Touch system in Galaxy S4, allowing users to interact with the touch screen by letting their fingers hover a few inches away from the display. By combining mutual capacitance, the on-surface normal touch sensing and self-capacitance, the Floating Touch in the Galaxy S4 expands the user experience of the display. It also detects touch inputs from gloved hands, a feature that was first introduced through Nokia’s Lumia 920 in 2012.

Galaxy S4 will be the first Full HD AMOLED display offering in the market. However, material lifetime, color balance and limited supplier base still need to be addressed for a larger market presence of OLEDs and stronger competitiveness against LTPS TFT-LCDs.

TFT LCD panel suppliers are forecast to ship 2.6 million 4K×2K LCD TV panels (also known as Ultra HD) worldwide in 2013, up more than 40-fold from 63 thousand in 2012, according to the latest NPD DisplaySearch Quarterly Large Area TFT Panel Shipment Report.

TFT LCD panel suppliers play a pivotal role in 4K×2K LCD TV adoption, providing innovative cost-effective technology solutions that will meet the anticipated demand for these devices. Specifically, they are focused on leveraging new technologies, such as high-transmittance cell designs, high-output driver integrated circuits (ICs), and high-efficiency backlight units and integrated up-scaling circuits for 4K×2K panels.

“To date, Innolux Corp. has been the most aggressive panel manufacturer in this market segment, developing a full line-up of 4K×2K panels in the 39" to 85" range,” noted David Hsieh, NPD DisplaySearch Vice President, Greater China Market. “Despite this, 4K×2K panel manufacturers’ shipments are primarily focused on 50", 55"/58”, and 65" sizes, which are expected to have the highest volume shipments, especially in China.”

Panel manufacturers are also looking to accelerate 4K×2K panel adoption by strengthening their relationships with LCD TV brands with more aggressive manufacturing and sales efforts.

“4K×2K LCD TV is the newest TV technology available, and in order for it to be successful, it will be critical for the supply chain to avoid falling behind when making their purchases, even if content is still scarce,” Hsieh added. “Some panel makers are also working with design houses to develop circuits built into the panel, to enable up-scaling of HD to 4K×2K content. This will help to drive the 4K×2K LCD TV market and encourage panel makers, especially those that have already started design-in work with TV brands in 2013.”

The Flexible Electronics and Display Center (FEDC) at Arizona State University and PARC, a Xerox company, today announced that they successfully manufactured the world’s largest flexible X-ray detector prototype using advanced thin film transistors (TFTs). Measuring 7.9 diagonal inches, the device was jointly developed at the FEDC and PARC in conjunction with the Army Research Lab (ARL) and the Defense Threat Reduction Agency (DTRA). This device will be used to advance the development of flexible X-ray detectors for use in thin, lightweight, conformable and highly rugged devices.

The TFT and PIN diode processing was done on the 470mm by 370mm Gen II line at the FEDC. This device showcases the Center’s successful scale up to GEN II, and the ability to produce sensors and displays using TFTs in standard process flows with the Center’s proprietary bond/de-bond technology.

The system design and integration was done at PARC. The flexible x-ray sensor was coupled to a flexible electrophoretic display and electronics to provide a self-contained, direct-view unit (including battery, user-interface and software). This system shows PARC’s capability to build user-defined prototype systems incorporating novel device physics, materials and technology. PARC has extensive experience in building large-area electronic systems, display and backplane prototypes and organic and printed electronics.

Formerly known as The Flexible Display Center at Arizona State University, the FEDC is a government – industry – academia partnership that’s advancing full-color flexible display technology and fostering development of a manufacturing environment to support the rapidly growing market for flexible electronic devices. FEDC partners include many of the world’s leading providers of advanced display technology, materials and process equipment. The FEDC is unique among the U.S. Army’s University centers, having been formed through a 10-year cooperative agreement with Arizona State University in 2004.

The employment of touch panels on mobile phones has paved the way for easy access to various operations. Moreover, there are increased demands for more specifications with the mobility, notably for outdoor readability. Touch panel makers are seeking ways to catch both greater specifications and lower cost at the same time, amid rapidly falling touch panel prices. Thus, the capacitive touch panel structure is undergoing the sea of changes.

Capacitive touch panels could be largely divided into the GG method (cover glass + ITO glass sensor), mostly used by Apple, and the GFF type (cover glass + two ITO film sensors). However, recent developments have introduced new structures that are more efficient in production and cost; ones with superior optical traits; and some with favorable weight/thickness.

Regardless of the type, the cover glass and touch sensor have a high cost ratio for all structures. As for 10.1-inch tablet PCs, the cover glass takes up 35% and the touch sensor around 30~32% for both GG and GFF types, which is why all the attention is being put on touch sensors.

Cost Ratio of Touch Materials by Structure

display market analysis

(Source: Displaybank, “Touch Panel-use ITO Film/ITO Glass 2013”)

With the rapid growth of the tablet PC market, the ITO film market has seen a staggering growth in demand with more manufacturers, which once insisted on glass sensors, switching over to film. The ITO film industry is even faced with supply shortages because it was late in responding to the exploding demand.

Meanwhile, some laptop models and all-in-one PCs have been employing touch panels with the launch of Windows 8. Since it is still in its initial stages, the touch panels are only employed on some of the high-end ultrabook models. But touch functions are expected to be increasingly applied on mid-end products. Considering that touch panels applied on mid-end products need to be cost efficient, GFF or GG types are most likely to be employed rather than the current G2. However, since there is an absolute shortage of large-sized glass sensor lines, and because mobile devices have to be light, GFF types have a higher chance of employment over the GG, which is why demands for ITO film is expected to grow. But along with such movements, large supplies of ITO film are forecasted for next year, suggesting a quick fall in ITO film sensor prices.

Against this backdrop, Displaybank analyzed and forecasted the ITO film/ITO glass market, technologies, and industry. The report forecasts the market by continuously observing and assessing the following issues:

ITO Sensor Market Forecast
Market forecast based on future touch panel strategies; cost simulations; possible supply capacity; and surrounding infrastructure of the major models, such as the iPad, the iPhone, the Galaxy Note, and the Galaxy.

Film Sensor
Considered enhanced outdoor readability through narrow bezel, use of sunglass film, and increased direct bonding; greater demands for fine patterning as a result of enhanced readability; the problem of resistance which is an obstacle to upsizing; and trends surrounding replacements.

Glass sensor
Considered the employment of thin-film glass; and how to maintain the side solidity to expand the sheet G2 market

AMOLED screens unveiled at CESAlthough active-matrix organic light-emitting-diode (AMOLED) televisions headlined last month’s Consumer Electronics Show (CES), shipments of these high-end panels will remain limited in the coming years, according to the Displaybank at information and analytics provider IHS (NYSE: IHS).

Shipments of AMOLED TV panels are expected to climb to 1.7 million units in 2015, up from 1,600 in 2013. While the jump in shipments is large, the total number of AMOLED panels by that time remains negligible compared to the vast number of liquid crystal display (LCD) panels being shipped.

Worldwide Forecast of AMOLED TV Panel Shipment (Millions of Units)

CES featured AMOLED TVs from leading manufacturers such as Samsung Electronics, LG Electronics, Panasonic and Sony, generating major excitement at the event, according to Displaybank.

“But despite ongoing efforts among these companies to achieve mass production and lower cost via various technology options, it is unlikely that most of the AMOLED TV prototypes announced at CES will be available in the market this year. The limited availability and high pricing of AMOLED TVs will restrict their shipments during the next few years.”

The only AMOLED TV likely to ship this year will be LG’s 55-inch flat Full HD model, the 55EM9700.

AMOLED bonanza at CES

Staking competing claims to be the first and largest in the world, 56-inch 4K AMOLED TV prototypes were each shown by Panasonic and Sony at the Las Vegas event. The sets boasted four times—hence, 4K—the resolution of current 1080p televisions. For the 4K OLED samples, both manufacturers used oxide thin-film-transistor (TFT) backplanes, which present lower manufacturing costs than low-temperature polysilicon (LTPS) backplanes.

Panasonic used the printing method on its 4K AMOLED TV, a simpler printing technology, making OLED production adaptable for a wider range of display sizes. In contrast, Sony used evaporation technology to deposit organic material in its top-emitting White OLED structure with a color filter. The panel was provided by AUO of Taiwan, which at the show also introduced its own 32-inch oxide TFT backplane with White OLED structure TV. Sony’s emission technology optimizes the OLED structure, which helps achieve better light management, enhances color purity and achieves higher contrast at lower power consumption levels.

Using different technological approaches, Sony and Panasonic were both able to make ultra-high-definition (UHD) 56-inch displays that reached 79 pixels per inch—twice the density of 55-inch full high-definition (FHD) displays used in the OLED TVs from LG and Samsung. For their part, Samsung and LG showed off 55-inch 3-D, FHD sets with AMOLED technology, coinciding with news that LG’s FHD TV will be available on the market by the first quarter this year. LG’s AMOLED TV utilized oxide TFT backplanes and the White OLED evaporation method, as it did in a prototype presented last year, eliminating the need for fine metal mask technology in OLED production.

White OLED provides an easier way to mass-produce OLED panels

Samsung, in contrast, used the LTPS TFT backplane and the RGB OLED evaporation method in its AMOLED TV prototype, similar likewise to what it did last year. Mainly applied in small- and medium-sized displays, sets with LTPS TFT backplanes and RGB OLED evaporation exhibit improved OLED performance, it is generally agreed. But with low yields and high costs, Samsung may find it difficult to launch AMOLED TVs in 2013 using these technologies.

Both Samsung and LG also unveiled their own curved 55-inch AMOLED TV prototypes at CES, with the sets boasting a 4-meter radius of curvature and Full HD resolution. Meanwhile, the success of Samsung and LG in implementing a large-sized curved OLED was thought to be a meaningful achievement in the display industry. However, both still face challenges with mass production, and market availability of curved OLED TVs is not a near-term possibility.

Yield improvement and cost reduction remain barriers

Also at CES, LG announced that its 55-inch Full-HD AMOLED TV will be available in the international market within a couple of months at a price of $12,000. LG has already started receiving preorders in its native South Korea, and the company claims it will start mass-producing the world’s first 55-inch OLED TV soon. While OLED TV makers all hope to become the acknowledged industry and technology leaders in their space, more improvements in technology, material and manufacturing appear to be needed in order to bring AMOLED TVs to the market.

In addition to technical and large-volume manufacturing challenges, OLED TVs also already face an uphill task of competing on prices with lower-priced, higher-resolution 4K LCD and even Full-HD LCD TVs. By the time AMOLED TV production achieves efficiencies in large-scale production, LCD TVs would have had an opportunity to become even more competitive in price and performance.

With still many challenges to be addressed despite many prototypes at CES, consumers are likely to wait a few more years before they buy their AMOLED TVs, Displaybank believes.

Imagers

Since 2010, there has been growth beyond expectations in the adoption of mobile devices, such as smart phones and tablets, which has called for larger volumes of CMOS image sensor chips to be produced. The resolution and miniaturization races are ongoing, and performance metrics are also becoming more stringent. In addition to the conventional pixel shrinkage, a “more than Moore” trend is increasingly evident. Resolutions of over 20 Mpixels are commercially available for mobile devices employing enhanced small-size pixels. Thanks to the innovative readout and ADC architectures embedded at the column and chip levels, data rates approaching 50Gb/s and a noise floor below single electron have been demonstrated. In addition to the conventional applications, ultra-low-power vision sensors, 3D, high-speed, and multispectral imaging are the front-running emerging technologies.

Back-side Illumination (BSI) is now the mainstream technology for high-volume, high-performance mobile applications, 1.12μm BSI pixels are available, and the industry is potentially moving towards 0.9μm pixel pitch and below. Additional innovative technologies outside of the traditional scaling include advanced 3D stacking of a specialized image sensor layer on top of deep-submicron digital CMOS (65nm 1P7M) using through silicon vias (TSVs) and micro-bumps. The importance of digital-signal-processing technology in cameras continues to grow in order to mitigate sensor imperfections and noise, and to compensate for optical limitations. The level of sensor computation is increasing to thousands of operations-per pixel, requiring high-performance and low-power digital-signal-processing solutions. In parallel with these efforts is a trend throughout the image sensor industry toward higher levels of integration to reduce system costs.

Ultra-low-power vision sensors are being reported in which more programmability and computation is performed at the pixel level in order to extract scene information such as object features and motion.

Lightfield/plenoptic commercial cameras, which have been available since 2010, are now gaining popularity and are being marketed for 3D imaging and/or all-in-focus 2D imaging. On-chip stereoscopic vision has been demonstrated through digital micro lenses (DML), paving the way to next-generation passive 3D imaging for mobile and entertainment applications, e.g. through gesture control user interfaces.

Significant R&D effort is being spent on active 3D imaging time-of-flight (TOF) applications to support requirements from autonomous driving, gaming, and industrial applications, addressing open challenges like background light immunity, higher spatial resolution, and longer distance range. Deep-submicron CMOS single-photon avalanche diodes (SPADs) have been developed by several groups using different technology nodes. They are now capable of meeting the requirements for high resolution, high timing accuracy by employing highly parallel time-to-digital-converters (TDCs) and small pixel pitch with better fill factor.

Ultra-high-speed image sensors for scientific imaging applications with up to 20Mfps acquisition speed have been demonstrated.

Multispectral imaging is gaining a lot of interest from the image sensor community: several research groups have demonstrated fully CMOS room-temperature THz image sensors, and a hybrid sensor capable of simultaneous visible, IR, and THz detection has been reported.

The share of CCDs continues to shrink in machine vision, compact DSC and security applications. Only for high-end digital cameras for astronomy and medical imaging do CCDs still maintain a significant market share.

Sensors & MEMS

A 4×4 array of sensing cells, developed by Dr. Peng Peng of Seagate Technology, from Flexible Microtactile Sensor for Normal and Shear Elasticity (IEEE Transactions on Industrial Electronics)

MEMS inertial sensors are finding widespread use in consumer applications to provide enhanced user interfaces, localization, and image stabilization. Accelerometers and gyroscopes are being combined with 3D magnetic-field sensors to form nine-degree-of-freedom devices, and pressure sensors will eventually add a 10th degree. The power consumption of such devices is becoming sufficiently low for the sensor to be on all the time, enhancing indoor navigation. There have been further advances in heterogeneous integration of MEMS with interface circuits in supporting increased performance, larger sensor arrays, reduced noise sensitivity, reduced size, and lower costs.

To address the stringent requirements of automotive, industrial, mobile, and scientific application, MEMS inertial sensors, pressure sensors and microphones are becoming more robust against electromagnetic interference (EMI), packaging parasitics, process voltage temperature (PVT) variations, humidity, and vibration.

Sensor interfaces achieve increasingly high resolution and dynamic range while maintaining or improving power or energy efficiency. This is achieved through techniques such as zooming, non-uniform quantization, and compensation for baseline values.

New calibration approaches, such as voltage calibration, are being adopted for BJT-based temperature sensors to reduce cost. In addition to thermal management applications (prevention of overheating in microprocessors and SoCs), temperature sensors are also increasingly co-integrated with other sensors (e.g. humidity, pressure, and current sensors) and MEMS resonators for cross-sensitivity compensation. Alternative temperature-sensing concepts find their way into applications with specific requirements not easily addressed by BJTs: thermal diffusivity-based sensing for high-temperature applications; thermistor-based and Q-based concepts for in-situ temperature sensing of MEMS devices and for ultra-low voltage operation.

MEMS oscillators continue to improve; phase noise is now low enough for demanding RF applications, 12kHz-to-20MHz integrated jitter is now below 0.5ps, and frequency accuracy is now better than 0.5ppm. Consumer applications are adopting new low-power and low-cost oscillators.

Biomedical

There have been continuous achievements in the area of ICs for neural and biopotential interfacing technologies. Spatial resolution of neural monitoring devices is being reduced utilizing the benefits of CMOS technology. IC providers are increasing their component offerings towards miniaturization of portable medical devices.

Telemedicine and remote-monitoring applications are expanding with support from IC manufacturing companies. The applications of such systems are not limited to services targeted for elderly or chronically ill patients; for example there are several technologies developed to enhance the way clinical trials are conducted by monitoring patient adherence and by improving data collection. Low power WiFi, and Bluetooth-low-energy is emerging as a standard wireless connection between portable communication services and wearable technology.

Smart biomolecular sensing is another major trend that marries solid-state and biochemical worlds together with the ultimate goal of enabling a more predictive and preventative medicine. With the help of the accuracy and parallelism enabled by CMOS technology, time, cost, and error rate of DNA sequencing may be significantly improved. Direct electronic readout may relax the need for complex biochemical assays. Similar trends are becoming increasingly evident in the space of proteomics and sample preparation.

Even for medical imaging, there is a trend from hospital imaging toward point-of-care and portable devices. A key example is in the space of portable high-resolution ultrasounds in which larger scientific imaging setups are being integrated onto the sensor by process technology (e.g. integrated spectral filters, CMUT). Another example is in the space of molecular imaging. The advent of silicon photomultipliers (SiPM) providing a solid-state alternative to PMTs enable the realization of PET scanners compatible with MRI, opening the way to new frontiers in the field of cancer diagnostics. More recently, SiPMs realized within deep-submicron CMOS technologies have allowed the integration at pixel- and chip-level of extra features, e.g. multiple timestamp extraction, allowing in perspective a dramatic reduction of the system cost.

Displays

The desire to put much higher-resolution and higher-definition displays into mobile applications is one of the display technology trends, and it is now opening a Full HD smartphone era.  440ppi high-definition displays are expected, even for 5-inch display sizes. Low-temperature polysilicon (LTPS) technology seems to have more merits over a-Si TFT technology. But a-Si TFT and oxide TFT technologies supported by compensating driver systems are being prepared to compete with it. Very-large-size LCD TVs over 84 inches, and UD (3840×2160) resolution are now the leading entertainment systems. 55-inch AMOLED TVs with Full HD resolution are also opening new opportunities in consumer applications.

As touch-screen displays for mobile devices become increasingly thin, capacitive touch sensors move closer to the display. The resulting in-cell touch displays come with reduced signal levels due to increased parasitics, and increased interference from the display and switched-mode chargers. Noise immunity is improved by adopting noise filtering and new signal modulation approaches.

This and other related topics will be discussed at length at ISSCC 2013, the foremost global forum for new developments in the integrated-circuit industry. ISSCC, the International Solid-State Circuits Conference, will be held on February 17-21, 2013, at the San Francisco Marriott Marquis Hotel.

large area flexible displaysTechnology directions in the field of large-area and low-temperature electronics focuses on lowering the cost-per-unit-area, instead of increasing the number of functions-per-unit-area that is accomplished in crystalline Si technology according to the well-known Moore’s law.

A clear breakthrough in research for large area electronics in the last decade has been the development of thin-filmtransistor, or TFT processes with an extremely low temperature budget of (<150°C) enabling manufacturing of flexible and inexpensive substrates like plastic films and paper.

The materials used for these developments have for a long time been carbon-based organic molecules like pentacene with properties of p-type semiconductors. More recently, air-stable organic n-type semiconductors and amorphous metal oxides, which are also n-type semiconductors, have emerged. The most popular metal oxide semiconductor is amorphous Indium Gallium Zinc Oxide, or IGZO, but variants exist, such as Zinc Oxide, Zinc Tin Oxide, and so on. The mobility of n- and p-type organic semiconductors has reached values exceeding 10 cm2Vs, which is already at par or exceeding the performance of amorphous silicon. Amorphous metal oxide transistors have typical charge carrier mobility of 10 to 20 cm2/Vs. Operational stability of all semiconductor materials has greatly improved, and should be sufficient to enable commercial applications, especially in combination with large-area compatible barrier layers to seal the transistor stack.

In the state-of-the-art p-type only, n-type only and complementary technologies are available. For the latter, all-organic implementations have been shown, but also hybrid solutions, featuring the integration of p-type organic with n-type oxide TFTs. Most TFTs are still manufactured with technologies from display-lines, using subtractive methods based on lithography. However, there is a clear emphasis on the development of technologies that could provide higher production throughput, based on different technologies borrowed from the graphic printing world like screen and inkjet printing. The feature sizes and spread of characteristics of printed TFT technologies are still larger than those made by lithography, but there is clear progress in the field.

The prime application for these TFT families are backplanes for active-matrix displays, including in particular flexible displays. Organic TFTs are well-suited for electronic paper-type displays, whereas oxide TFTs are targeting OLED displays. Furthermore, these thin-film transistors on foil are well-suited for integration with temperature or chemical sensors, pressure-sensitive foils, photodiode arrays, antennas, sheets capable of distributing RF power to appliances, energy scavenging devices, and so on, which will lead to hybrid integrated systems on foil. Early demonstrations include smart labels, smart shop shelves, smart medical patches, etc. They are enabled by a continuous progress in the complexity of analog TFT circuits targeting the interface with sensors and actuators, to modulate, amplify and convert analog signals as well as progress in digital TFT circuits and non-volatile memory to process and store information.

In line with this trend, ISSCC 2013 features three papers representing the latest state-of-the-art of organic thin-film transistor circuits. A front-end amplifier array for EMG measurement is demonstrated for the first time with organic electronics in paper 6.4. Transistor mismatch and power consumption of the amplifier are reduced by 92% and 56%, respectively, by selecting and connecting the transistors trough a post-inkjet printing. Papers 6.5 and 6.6 present advances in analog-to-digital converters for sensing applications. Papers 6.5 demonstrates the first ADC that integrates on the same chips resistors and printed n and p-type transistors. The ADC achieves an SNDR of 19.6dB, SNR of 25.7dB and BW of 2Hz. In Papers 6.6, an ADC made only with p-type transistors is presented that has the highest linearity without calibration and that is 14 times smaller than previous works using the same technology.

This and other related topics will be discussed at length at ISSCC 2013, the foremost global forum for new developments in the integrated-circuit industry. ISSCC, the International Solid-State Circuits Conference, will be held on February 17-21, 2013, at the San Francisco Marriott Marquis Hotel.

January 22, 2013 – Reports are circling around Apple’s supply chain of a potential shift in the company’s display strategy for its future iPhones and iPads — moving back to LCDs and away from touch panels — but a drastic realignment of its supply chain is probably not likely, observes DisplaySearch.

Calvin Hsieh, senior analyst at DisplaySearch, cites a report from China that Innolux has delivered "touch on display" samples for the iPhone, another China report that Innolux and AU Optronics have provided "one-glass solution" (OGS) samples for the iPad Mini, and his firm’s own analysis that the iPhone 5 uses in-cell touch technology but the iPad mini uses a glass/film dual ITO (GF2, or DITO) structure. With both those processes struggling to attain good yields, could Apple end up changing its display technology adoption midstream?

TOD is a proprietary on-cell touch technology developed by Innolux in which the sensor is located on the upper glass (the color filter substrate) beneath the top polarizer. On-cell touch combines both LCD and touch so it must meet Apple’s LCD display requirements; Hsieh notes, adding that Innolux accounted for less than 10% of iPhone 4 display shipments (3.5-in, 960×640). "If Apple were to adopt TOD, it would very likely request that Innolux share its technology, structure or even patents with Apple’s other LCD suppliers in order to ensure adequate supply," he writes," and Apple also probably would want to take over the controller IC and algorithm from any Innolux partners (e.g. Synaptics). Apple already owns DITO patents, he adds.

The OGS display technology is an even more complex problem, Hsieh points out. OGS integrates the touch ITO sensor circuits into the cover glass, via two possible methods: a piece type such as "touch on lens" (TOL) or a sheet type, each accomplished with a different process. Either way the X-Y sensor patterns are on the same side of the substrate, so it’s called a "SITO" structure or "G2." Touch panel maker TPK owns patents for the piece-type OGS method, and claim they have key SITO patents as well and are suing Nokia and Chinese panel maker O-film, Hsieh notes; whether the aforementioned Innolux-AUO partnership could produce the technology given the TPK patents is unclear, he says.

There’s more to Apple use of OGS display if it chooses that route. Sheet-type OGS has a compressive cover-glass strength of 500-6600 Mpa; Corning’s IOX-FS and Gorilla glass have 600-700 Mpa for smartphone sizes and cannot be used in sheet type, Hsieh says. Piece type has the higher CS value but are difficult to mask-stamp and align under lithography, and throughput may be low.

Among iPhone 5 panel suppliers only LG Display offers everything from in-cell touch LCD to cover glass lamination (consigned by Apple), Hsieh notes. Other in-cell touch LCD makers Japan Display and Sharp rely on partners for the cover glass. If Innolux and AUO continue with their OGS partnership, they have a choice:

  • An integrated offering of LCD, OGS sheet patterning (cover glass with SITO sensor), and lamination let Apple specify the IOX-FS glass sheet with compressive strength of Gorilla 1; "In this scenario, LG Display will never give up and must be one of the suppliers," he notes.

  • Integrate the LCD, OGS piece-type sensor patterning, and lamination, using consigned cover glass pieces from other finishers (e.g. Lens One). The challenge here is expanding tools, throughput, and yield for piece-type patterning, to be acceptable for the iPhone’s >100M unit base.

All that is somewhat speculation, though, because long-term Apple touch supplier TPK already "has excellent OGS sheet and piece-type technology, and high lamination yield rates," and is unlikely to simply hand over that business to new entrants. "Although AUO and Innolux have advantages as LCD makers and can shorten the supply chain by producing LCD and touch at the same time, TPK has strength in OGS integration from sensor patterning, cover glass finishing (for sheet type), to module lamination," Hsieh writes. "Thus, there is a good chance that TPK will once again be a key touch supplier to Apple if it decides to change touch structures."