Touch Technologies to Soar in the Coming Decade
By Tom Morrow, EVP, SEMI Global Emerging Markets Group
Driven by sales of smart phones, tablet computers, ebooks and other devices, touch technologies will rise by a factor of seven in the next three years creating new business opportunities for suppliers of vacuum deposition, screen printing, laminating, etch, sputtering, inspection, and other systems and equipment. With the success of Apple’s iPad, the future of conventional keyboards is even being questioned and a wave of new touch systems are being developed that will revolutionize how people interact with technology.
Up to 24 new iPad-rival tablets are expected to become available between now and Q1′11, from companies including Dell, Acer, HTC, Cisco, HP, Nokia, Samsung, Asus, RIM, Toshiba, and more. Many of them will feature innovative touch screen panels and no keyboard. Some analysts predict that these tablet PC sales will grow more rapidly than smart phone sales and will probably constitute a larger market within five years.
iSuppli estimates that shipments for touch screens for tablets, mobile phones and other products will rise 5,000 percent in 2010 to 8.9 million units. Shipments of transparent touch screens will then increase to 63.9 million units by 2013. DisplaySearch reported that total touch screen module revenue will grow from $4.3 billion in 2009 to nearly $14 billion by 2016, a compound annual growth rate of 18 percent. Due to the popularity of the iPad, the market is currently experiencing capacity shortages and a wave of innovation and investment is expected to hit the industry.
In a recent workshop on touch technologies hosted by FlexTech Alliance at the recent SEMICON West event, participants learned about the key applications, trends, and technology drivers that are behind this technology wave. Instructors Abbie Gregg from Abbie Gregg, Inc. and Geoff Walker from NextWindow presented technical and application overviews of all of the 13 transparent touch technologies that are used on top of displays, as well as an introduction to the newest “in cell” touch technologies. The technologies covered were: analog and digital resistive, surface and projected capacitive, surface acoustic wave (SAW), traditional and waveguide infrared, optical, acoustic pulse recognition (APR), dispersive signal technology (DST), force sensing, in-cell, and vision-based.
Pre-iPad, most of the slate PCs on the market relied on either active digitizers or resistive screens for touch functionality. According to DisplaySearch, in 2009 all forms of analog resistive technology reached over $2 billion and 452 million units, representing 48 percent of the revenues and 74 percent of total units. Projected capacitive screens used in the iPad, which only appeared in this market in 2007, had a very small share, but now are expected to outpace resistive technology.
Nonetheless, digitizers and resistive markets continue to grow. Both of these technologies, as well as others still in the development stage, will take increasing shares of the market in the coming years, as vendors attempt to differentiate their products through function and cost.
Touch Screen Technology Market Share by Revenues 2009
Source: DisplaySearch 2010 Touch Panel Market Analysis
The touch screen industry is extremely dispersed with many companies pursuing either single or multiple touch technologies. Approximately 90 companies are manufacturing resistive technologies. According to Gregg and Walker, projected capacitive technology has an estimated 56 suppliers, which is nearly twice as many as last year’s 27 suppliers.
The principle factor in the rapid shift to projected capacitive technology is multitouch technology. Multitouch refers to a touch system's ability to simultaneously detect and resolve a minimum of two or more simultaneous touch points. The human interactive experience is dramatically improved when multiple touches can be detected and fully resolved. Mainstream exposure to multi-touch technology occurred in 2007 when the iPhone gained popularity. Today, most operating systems support multitouch, including Mac OS X, Windows 7, Apple's iOS, Google's Android, Palm's webOS, Symbian OS, Microsoft's Windows Phone 7, and BlackBerry OS 6.0.
After the display, the next most expensive component on the iPad is the capacitive touch screen assembly, reportedly supplied by Taiwan’s Wintek Corp for around $30. Other makers of such assemblies include Sintek Photronic Corp., TPK Solutions Inc., Touch International and Young Fast Optoelectronics Co. Ltd. News reports indicate that Wintek is currently expanding its production lines in the Chinese cities of Dongguan and Suzhou to catch up with the demand, adding 1.6 million touch screens to the monthly supply.
A capacitive touch screen panel consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide (ITO). Human touch is a conductor that will distort a screen’s electrostatic field, measurable as a change in capacitance. Different technologies can be used to determine the location of the touch. The location is then sent to the controller for processing. Projected capacitive touch technology is a capacitive technology which permits more accurate and flexible operation, by etching the conductive layer. An X-Y grid is formed either by etching a single layer to form a grid pattern of electrodes, or by etching two separate, perpendicular layers of conductive material with parallel lines or tracks to form the grid. The use of an X-Y grid permits a higher resolution than other technologies.
iSuppli reports that three separate ICs are used to support the touch screen display which indicates that the design is in still in its infancy, and suggests that future integration into a single device is possible. Future versions of the iPad are likely to use a single-chip solution for supporting the touch screen functionality, creating opportunities for suppliers that can offer such products.
Capacitive sensing electrodes can be embedded in LCD display manufacturing either through in-cell or on-cell (out-cell approaches laminate the touch screen directly on top of the LCD screen). In-cell integration requires a change in the LCD fabrication method to embed the charge-sensing electrodes inside the LCD cell. Out-cell integration is an addition to the color filter process that places an array of indium tin oxide (ITO) or alternative transparent conductors on the top surface of the color filter substrate.
As Gregg and Walker observe, “there is no perfect touch technology.” Each of the 13 current touch technologies has unique usability, performance and integration characteristics. What is optimal for automotive, POS terminals or interactive signage may not be optimal for slate computers or mobile phones.
What most observers do agree on, however, is that this market is very early-stage. Today’s manufacturing and supply solutions are almost assured of being upgraded, enhanced and overhauled over the next several years as the total market triples. The success for the iPad, as well as the many smart phones on the market, have demonstrated that touch technologies now rival — if not exceed — the functionality and user preference of keyboards. New systems are being developed with the user interface as the primary design consideration — not the motherboard. Rivals to the iPad and new touch-enabled applications are sure to emerge in the coming years. For equipment and materials suppliers, opportunities for innovation and profit abound.
For more information:
FlexTech Alliance www.flextech.org
Abbie Gregg, Inc. www.abbiegregg.com
Join the SEMI-sponsored online community for printed and flexible electronics at:
September 7, 2010