Conductive inks: major innovation themes and trends

Conductive inks: major innovation themes and trends
An often overlooked fact about the conductive industry is that it has seen significant innovation over the past decade. Indeed, the industry has a long history of developing new materials and formulations in response to changing market needs and new applications.
At IDTechEx, we have been closely tracking the developments in this industry all around globe. Indeed, our report - Conductive Ink Markets 2017-2027: Forecasts, Technologies, Players - is the result of years of research as well as industry experience. Here, in this article, we will briefly outline, in very broad terms, some major developments in the industry. For more details, please refer to the report.
Nano inks: nanoparticle inks have been around for well more than a decade. The value proposition was in offering more-for-less, i.e., offering high conductivity with a lower metal content. This, it was argued, compensated for the higher production cost and price compared to incumbent pastes with micron- or sub-micron-sized fillers.
The original promise however did not live up to expectations and the incumbent technology proved too resilient and adaptive. Consequently, in the past decade, we observed the rise and fall of many start-ups, and the opening and closing of numerous nanoparticle ink projects at large companies. The different versions of our report Conductive Ink Markets 2017-2027: Forecasts, Technologies, Players in the past years reflect this changing competitive landscape.
The technology is however slowly finding its foot into the market. This is partly driven by the emergence of new applications and deposition processes. Just two examples in recent years are IC packaging EMI shielding and aerosol deposition: both continue to be hot topics and many are engaged in serious late-stage qualification processes.
Copper ink/pastes: Price reduction is self-evidently the main driver for the development of copper ink/pastes. This motivation became stronger when silver prices peaked around 2011, triggering a global wave of copper-development around the world. Numerous innovative (and successful) curing/sintering processes were launched including the rapid photo-sintering to avoid copper oxidization. Novel formulations were also developed to enable in-air curing or gas phase metallization.
Copper however turned out to be an inexperienced technology compared to silver. Too many pre-mature promises were made in terms of price differentials with silver, air stability and curing conditions, leaving copper faced with a credibility gap. Here too, as we kept watching the industry, companies and projects came and went all over the world. Indeed, products failed to sell in large volumes.
This too may be about to change. A new generation of copper ink companies are emerging. Indeed, the industry has accumulated increased experience, particularly on the application side. And more importantly, new annealing equipment are being installed, finally opening the door to sales of copper inks, which were never a drop-in replacement.
Inks for fine line formation: The trend to narrow printed lines appears perennial. In touch screen edge electrodes, for example, market trend pushed the requirements beyond the capabilities of standard inks and screen printing. The industry, however, responded, offering photo-patternable and laser-cut inks, enabling it to stay competitive with alternative subtractive processes.
Another example is the transparent conductive film (TCF) industry. Here, direct printing was not a viable technology for metal mesh due to its wide linewidth. However, now progress on gravure offset printing and optimized sub-micron inks enable direct printing of 5um lines. This may not be a radical innovation but is an important incremental one. Interestingly, the conductive ink industry is full of such examples of tailoring inks into specific applications.
Stretchable inks: This is relatively a new development, driven partly by the rising interest in electronic textiles (e-textiles) and in-mold electronics (IME). In the e-textile and related markets, the ink must withstand numerous significant stretching events, whereas in the IME application it needs to withstand a one-off elongation event.
Both these applications are emerging, and the suppliers have responded with the development of new materials. Indeed, three years ago only two or three companies offered such inks, but now most players have either launched a product or demonstrated capability.
These young applications are also in a state of flux. For example, in e-textiles, the figures-of-merit are also not yet fully known. Indeed, the market itself is still uncertain as to how much stretchability and washability is required, what conductivity levels are needed, what printing/transfer process is best suited, what substrate/encapsulation are to be employed, and so on. This is characteristic of such nascent markets in which many are still in the exploration phase.
The progress and innovation is taking place on every front in the conductive ink and paste industry. New applications emerge, establishing new needs; whilst old applications raise the performance bar, demanding better or different inks. Even in highly competitive mature markets such as photovoltaics, incremental improvements are often what gives suppliers a short-lived performance advantage.
Some technology changes are more fundamental, often taking long times, particularly when seeking to un-sit a resilient incumbent in a technology push. In contrast, some developments are notable modifications of existing technologies. These have shorter time-to-markets, particularly when they have a market-pull. And some developments themes are a mainstay of the industry such as low-temperature and fast annealing.
Indeed, the developments are so diverse that we cannot hope to capture them all in the article. For more details, however, we recommend the IDTechEx report - Conductive Ink Markets 2017-2027: Forecasts, Technologies, Players. Here, you will find our analysis on numerous emerging technologies and applications. Furthermore, we will learn detailed ten-year market forecasts for 25 applications.