Metal mesh transparent conductor (TC) materials have come into their own in the past couple of years. They have become a viable alternative to indium tin oxide (ITO), showing superiority in effectively spreading voltage across a large panel, particularly for touch-screen sensors but also large-format displays.
This technology also is inching its way across the competitive battlefield in search of new growth avenues, encroaching on the turf of not only incumbent indium-tin-oxide (ITO) but also where alternative TCs have been making market headway. It’s progressing with smaller (sub-5µm) line widths, for example, where ITO and other alternatives (notably silver nanowires) have staked claims.
Advantages and Challenges for Metal Mesh TCs
The metal mesh business is something of a zoo, with a growing number of offerings in silver and copper. A big open question is what mesh-like solutions will the market finally settle on. For the most part we are talking silver meshes here, although some suppliers have been working on copper meshes.
Metal mesh TCs arguably are the best option for large touch panels from a resistivity point of view, and suppliers make significant performance claims about superiority to ITO in terms of transparency, conductivity, flexibility and the ability to be integrated into a touch sensor. They’re not easy to fabricate, but they are easier than some of the other proposed ITO alternatives. Electrodes and border connections are printed simultaneously, and R2R printing can be deployed for both coating and patterning to keep both the capital and operating cost low in the fabrication of meshes low.
From a technology perspective, the big challenge with metal mesh that it is rather expensive to customize; it has to be matched to the display, where any changes (e.g. pixel patterns or resolution) require a different metal mesh sensor. The bugaboo of moiré patterns seems to have been largely resolved by adjusting the mesh spacing and angles. Visible grid lines have been noted in the past but the latest generation of meshes is much better.
Opportunities for Metal Mesh: Large Touch Panels and Beyond
The design of touch sensors and their integration into displays are in the midst of change. Touch sensors are being redesigned to lower costs and improve efficiency, while their placement in the display/sensor integration is evolving.
With reported resistance in the 0.1-30 Ω/sq, metal mesh TC grids are excellent for use with large (i.e., more than 8-inch) touch panels and cover glass applications in the display sector. There is also less signal degradation when there are multiple touches on the same row or column, essential for large displays that require 10-20 or more simultaneous touches.
Outside of large touch displays, though, are there any other promising market opportunities for metal mesh TCs?
There is some hope that metal meshes would be a better TC for OLED applications, particularly ones that need larger panels: TVs, lighting, and solar panels. Transparent conductors are typically used for the anode in the OLED stack, but as in other areas of the display industry, there is debate about replacing ITO with other TC materials. In particular, metal meshes and Ag nanowires/nanoparticles offer mechanical and electrical properties that could be a better fit with active OLED materials.
n-tech Research believes that OLEDs are a much better prospect for alternative TC sales than LCDs, even if OLED panels haven’t shown any big signs yet of using non-ITO TCs. The fact that OLED panels inherently use less TC material than LCD panels is really more of a concern for ITO suppliers — alternative TC suppliers would gladly take any small portion of the large volumes promised by larger OLED panels such as TV and lighting.
At the same time, consumer adoption has been uninspiring over AMOLED displays for cell phones, tablets, and televisions, even as other types of high-quality TVs such as quantum dot-based ones have arrived on the market.
For OLED lighting, there is still not all that much to show in the marketplace, but we are much more optimistic about this space today than we were just a couple of years ago, primarily because of new production facilities at Konica Minolta, and similar moves we expect (or at least to be considered) by LG Chem, Philips and others.
Suppliers in Flux: Is One Better Than Two?
Recent setbacks in the metal mesh market suggest the technology might not penetrate the TC market as fast as once hoped, and the latest news and rumors invite a number of questions about the sector. Earlier this year we tracked the following headlines:
- Atmel decided to shut down its XSense touch sensor business
- UniPixel reported no revenues in 2014, and re-revised its chronically late production targets to mid-2015
- Reports emerged suggesting O-Film and Fujitsu were having issues with supply chains and finding customers
Two of those loose threads are now weaving together. In late April 2015, UniPixel’s announced its acquisition of Atmel’s XSense touch sensor assets, while also canceling the joint development program with longtime partner Kodak for its own InTouch sensors. Kodak apparently will push ahead on the technology itself and hopes to be making touchscreen sensor film by the end of 2015.
Atmel has actually been in commercially available products (Asus and HP tablets, plus others in development) and generating revenues, two things UniPixel has singularly struggled to achieve. Thus, UniPixel now pledges to generate more than $10 million in revenues in 2015 and be profitable in 2016. Atmel and partners couldn’t sustain the XSense business, so how will UniPixel make it profitable? Part of that, the company suggests, will be decoupling XSense touch sensors from higher margin expectations as part of Atmel’s larger business. More will come from solving “cost bottlenecks” that UniPixel says it has identified, and claims it can solve by applying its own process know-how.
Feeling the Pricing Pressure
Despite the performance advantages of metal mesh technology, much of the competition is still on price, at least in the critical touch sector. Competing on price is something that no new technology firm would ever want to do, but it has become especially acute in the metal mesh TC sector thanks largely to ITO price declines. Describing its motivations to unwind the Kodak JDP, UniPixel underscored that the pricing and margin pressures in today’s marketplace don’t leave room to share profits with a third party.
That also invokes another trend relevant to supplying touch sensors. Cell phone display panel makers are increasingly building touch sensors directly into the display panel, and not sandwiched between a display glass and top cover glass. That’s a clear problem for glass-film touch sensor makers, mesh or otherwise.
The Bottom Line: Watching and Waiting
The bottom line for us, here in early 2015, is that the metal mesh TC sector has advanced ahead somewhat in development and commercialization, but also some recent retrenchment. Overall, though, we do remain positive about the prospects for metal meshes in the TC sector.