It All Starts With Silver

Much of real world printed electronics today uses silver pastes or inks; the focus here is on thick-film (i.e., screen printed) processes, but silver inks are also heavily targeted towards the more "trendy" ink-jet applications as well. The prominence of silver in the printed electronics world is partly because of its long history in thick film electronics, and this has led to a deep understanding of how silver can be turned into inks. Even more so, it is a tribute to the fact that silver is the most conductive substance known to man. It is easy, then, to see how silver inks are viewed as having an important role in the printed electronics world to come by most insiders.

Impacts of rising silver prices:

Be that as it may, the opportunities presented by conductive silver inks now look different than they did a year ago. The villain here is the dramatic rise in the price of silver, which NanoMarkets believes changes the prospects for silver inks significantly. Of course, the future of commodity prices is pretty uncertain right now. But there seems no reason to suppose that silver is going back to the price of a few years ago. One expert quoted recently in Forbes said that silver prices could average $17 per ounce in 2008 against $13.38 in 2007.

The causes here have nothing to do with electronics as such, but are more financial in nature. They include the weak dollar, inflation fears and increased investor interest in commodities as a whole. Rapid improvements in the economies of both India and China have something to do with it also. But that doesn't mean that higher prices for silver inks won't have an impact on printed electronics.

For one thing, printed silver has been seen as an enabling technology for one of the most cost-sensitive applications in printed electronics; RFID. If we can inexpensively print RFID antennas using silver inks, it has been held that price points for RFID will decline and the dream of ubiquitous item-level RFID will come a lot closer to reality.

With the prices of silver at current levels, silver conductive ink makers and the firms that actually print or plan to print RFID tags have been recalibrating their revenue expectations. High prices for silver will surely not kill the printed RFID tag business altogether. Antenna printers are becoming less ambitious and are looking to the "high end" (i.e., less price sensitive sector) of the RFID market; where tags are used for animal tracking or inventory management of very expensive items. These are much lower volume markets though, and it may take some big changes in the world economy before the prospects for silver inks in the RFID space look as good as they did a couple of years back.

In the meantime, silver ink makers have started to look around for new opportunities and one of the best is also one of the most obvious; photovoltaics (PV). Because of the boom in cleantech investment, PV is an application on which many materials and electronics firms have their eyes these days and screen printed silver is the traditional way to make the front contact for conventional crystalline silicon PV. So silver already has an "in" in the PV market.

NanoMarkets sees a strong opportunity in PV for silver ink makers in the next few years, but it comes with some important caveats. First, don't be surprised if the PV boom turns out to have a bit of a bubble aspect to it. Markets can go on growing at 60 percent AAGR for just so long. In addition, while thick-film silver is a conductor of choice in conventional (i.e., crystalline silicon) PV, it is not widely used for thin-film PV, which is by far the fastest growing part of the PV industry.

There are certainly many other application areas in which printed silver has an enduring role. In recent interviews with major ink makers, for example, medical applications came up a lot; medical patches and medical imaging electrodes, in particular. However, these and many other applications for silver inks have only limited potential because they are not (potentially or actually) mass markets. NanoMarkets' recent report on silver inks predicted that by 2015, RFID will account for more than half of the conductive silver ink consumed worldwide , while PV will account for another 10 percent or so. Most of the rest of the conductive silver ink market will be accounted for by the very diverse range of established thick-film applications that range from car heaters to PCBs.

So, hunting for new applications may make sense up to a point. If you are gaining new revenues by selling an existing ink product into a new market that is usually a good thing. However, most of these novel applications will turn out to be niches only.

In the end, we expect that the conductive silver ink market will do quite well, almost tripling in size between now and 2015. By 2015 NanoMarkets' estimates place the market for silver conductive inks at about $2.4 billion.

But to achieve that kind of growth, RFID will have to take off. Lower-or at least stable silver costs-will certainly help to make this happen. But what will really have to happen is that RFIDs will have to prove its worth at the applications level; in inventory management, tracking, ID, etc. It always takes longer for IT systems to prove their worth than their early advocates expect; remember what happened with PCs. On the other hand, as government and industries of all kinds begin to dabble with RFID they are going to find new applications for it. Again, this is typical of what happens with new IT technologies. These new applications will add to the value proposition of RFID and as the RFID business matures the risks of adoption will become lower. End users will become more willing to buy into RFID technology and the high cost of silver ink to print them is likely to become less important.

All That Shines is Not Silver: A Future for Copper Inks?

Despite the escalation of silver prices, NanoMarkets believes silver conductive inks will remain the most important metallic ink for printed electronics (PE) for the indefinite future. There is simply no alternative material that comes close when one considers conductivity per dollar. But in the current market, one cannot blame ink makers for looking for alternatives all the same and the search invariably leads to copper, which is almost as conductive as silver and must less expensive. The problem with copper is that (unlike silver) its oxide is not conductive and in powder form copper is a somewhat dangerous material that tends to self combust. (Copper powders would be used to make inks.)

Copper thick-film inks and pastes have been around for decades, but few firms are making them a priority in their product development. One minor exception to this rule can be found in a recent announcement from the Applied Nanotech (ANI) subsidiary of Nano-Proprietary. This announcement identified ANI's new relationship with NanoReady to create copper nanoparticles in volume for use in "ink-jettable copper inks for the flexible electronics, solar cell, digital printed circuit board (PCB) and many other industries."

Other than this announcement, we have come across no conductive ink maker who thinks that pure copper inks are a huge opportunity. Where NanoMarkets has found a lot of interest is in silver-coated copper inks. Again, as a thick-film product, these have been around for a long while and they seem to offer a way to combine the best of silver (high conductivity) with the best of copper (low cost). However, what is still unclear to us is just how serious the current interest in silver coated copper inks actually is. Will it evaporate if silver prices begin to decline? And how far do they have to decline before this type of ink is de-emphasized? It is clear that with silver prices so high there are some real opportunities here, but they are also associated with high risks, especially given the many difficulties that copper experiences when it is converted into ink.