Feeding a Touch-Panel Hungry World
Just this year, we have seen a virtual explosion of touch panel growth fueled by the world’s seemingly insatiable appetite for touch-enabled devices. It is hard to say whether this growth will be tempered or continue amidst the promise of even greater adoption of mobility devices and invention of new “must have” products. In either case, touch technology is now a permanent member of the flat panel display family.
I marvel at how the industry has evolved over the past few years. Three years ago, I had the opportunity to take a position as Head of our Web Products Group in Germany (the group that makes our roll-to-roll vacuum deposition tools). At that time we strengthened our focus on Flexible Electronics, looking at opportunities in flexible solar, displays, printed circuit boards and several different transparent conductor-based applications including touch screen elements. Ironically, the team had already been addressing this market for years, with sales of roll-to-roll sputtering tools for indium tin oxide (ITO) since the early 1980s, but it had remained relatively small and stable due to modest annual growth in resistive touch technology.
It wasn’t until we all discovered the wonders of multi-touch in phone and tablet devices that the market broke away from its slow and stable pattern. The adoption of projected capacitive touch technology, which enables excellent multi-touch performance, created frenzy among manufacturers to add capacity. Initially, the industry converted older Color Filter lines to touch panel production, then we started seeing rapid demand for our SmartWeb roll-to-roll sputter system for both resistive and projected capacitive touch manufacturing, and these past several years we have been shipping record levels of our New Aristo and AKT Aristo Twin systems specifically designed for touch element production, representing compelling growth in both film-based (roll-to-roll) and glass-based products.
Last year, I moved down the hall as General Manager of the Display PVD Group, where my participation in touch panel technology continues, now from the glass side. It is remarkable how similar, and yet how different, the two substrate types are when it comes to touch. Both utilize latest state-of-the-art ITO deposition technology, both incorporate additional films to improve ITO performance (e.g. SiO2, metals) and both are used in projected capacitive touch panels in mobile phones and tablets. Yet, substrate handling is unique for each, the optical properties are optimized exclusively and the applications for each lean in different directions. For example, film-based devices are thinner, lighter and more resistant to physical shock; whereas glass-based devices are more transparent and more scratch resistant. Of course, both approaches are actively working to minimize their respective weaknesses as glass is getting thinner and lighter, while film is becoming more transparent and using better hard coatings.
Independent of their differences, both film-based and glass-based approaches are helping the industry evolve with greater integration of functional layers. Projected capacitive touch requires that the transparent conductor layer (e.g. ITO) be patterned. The patterns are not complex by semiconductor or LCD standards, but they can be discerned by the human eye (not necessarily best for the underlying display quality). To address this, additional layers can be added to optically hide these patterns without degrading the overall optical quality of the touch panel element. Even better, these additional layers add anti-reflective characteristics that improve the viewing experience of the display. By incorporating these additional layers in the same PVD (sputter) machines that deposit the ITO, SiO2 and/or metals, the end-product manufacturers have the opportunity to eliminate additional materials that might otherwise be integrated separately as laminates and/or wet coatings.
For the indefinite future, this will continue to be a very dynamic industry, growing quickly and bolstered by a variety of exciting technologies. It is a great time to be part of this value chain, helping to feed our appetite for a visual, interactive world.