Green plasma process technology for manufacturing of flexible electronics

PROJECT DESCRIPTION

BACKGROUND

Increasing resource efficiency will play a major role in securing growth and jobs in Europe. It will bring major economic opportunities, improve productivity, drive down costs and boost competitiveness.

The market for flexible electronic products is predicted to grow sharply. The manufacturing industry currently uses vacuum plasma deposition systems (vacuum PE-CVD) which have precursor-to-product ratio efficiencies of 20% at best. At least 80% of the raw materials leave the reaction chamber as exhaust or are deposited on reactor system components. As a consequence, the raw material waste stream of highly toxic precursor chemicals (aluminium oxide silane) is predicted to reach 12 000 tonnes by 2021. Moreover, the vacuum plasma process requires pumping systems and regular cleaning procedures to remove the depositions from reactor system components. Both aspects reduce the efficiency of vacuum PE-CVD in comparison with the new technology, APG-CVD: atmospheric pressure glow plasma for chemical vapour deposition.

OBJECTIVES

The main objective of Life_Green_plasma project was to demonstrate a new environmental-friendly process technology for manufacturing flexible electronic components. This innovative technology platform would have the potential to replace the traditional PE-CVD technology used for the deposition of thin functional coatings with electrical, optical, mechanical and moisture barrier properties. It was expected to lead to a reduction of raw material (precursor) usage and CO2 emissions by more than 90%.

Specifically, the project aimed to:

Construct an APG-CVD Process Demonstrator, as a moveable prototype system for on-site demonstrations of APG-CVD plasma process performance. It would demonstrate the quality of the product, robustness and process flexibility, efficiency of raw material use, safety and ease of operation, and the process’s adaptability to specific customer requirements;

Demonstrate the listed technical and environmental advantages of the APG-CVD plasma process for European industry active in the field of flexible electronics, through on-site demonstrations and comparison of the APG-CVD plasma process performance with the performance of traditional vacuum plasma systems;

Quantify environmental, technical and economic advantages of APG-CVD plasma technology through demonstration, product analysis and calculations based on specific customer situations;

Scale-up processes to a width of 120 cm in pilot plant process stability trials, leading to a robust process window setting; and

Demonstrate large-scale manufacturing opportunities for different functional layer mixtures, varying aluminium oxide thickness (1-200 nm), composition (SiOx, TiOx, ZnO, SnO), porosity and surface hydrophobicity.

RESULTS

The Life_Green_plasma project developed a demonstrator Atmospheric Plasma Glow Chemical Vapour Deposition (APG-CVD) technology for the manufacturing of flexible encapsulation foils for photovoltaic cells. This novel demonstrator was shown to be capable of reaching webbing speeds of up to 50 m per minute. It is a user-friendly tool that can be operated by a non-specialist, making it ideal for demonstrating all the advantages of the technology to licensees. APG-CVD technology uses a wide range of pre-cursor chemical solutions that allow licensees a great deal of freedom in how they apply the technology. Now in its pilot plant phase, it has been designed to substitute the existing vacuum PE-CVD technology for thin film photovoltaic process steps and to accelerate the introduction of large-scale, low-cost, roll-to-roll manufacturing systems. The APG-CVD process can thus be benchmarked against the environmental performance of conventional process. The following advantages were shown:

Energy savings of over 95%, supported by the introduction of sustainable photovoltaic systems;

A non-toxic precursor conversion rate of more than 80%, significantly higher than the conventional conversion rate of just 20% that yields far higher levels of toxic waste;

Low cost elements such as nitrogen and oxygen can be used to deposit high-quality SiOx films;

Organic solvents for dissolving conventional precursors (such as silane, SiH4) can be avoided, resulting in toxic gas emission savings of up to 10 tonnes ethanol per km² of cells;

Environmental friendly precursors such TEOS can be utilised;

Atmospheric roll-to-roll processing can be integrated with any atmospheric coating technique, such as wet coating techniques; and

The results can be scaled up to a web width of 2-3 m pilot plant.

During the project, the beneficiaries took part in 38 conferences and events, and arranged more than 30 visits to Fujifilm's centre in Tilburg where the new technology was demonstrated. Such visits led to the signing of eight non-disclosure agreements with key stakeholders that were eager to adapt the technology to their needs.

The demonstrator can be applied to the production of a wide range of products, and specific test samples and sample characteristics are provided to each interested customer. Currently, the project team are further developing the technology in close collaboration with interested stakeholders. The market for flexible encapsulation foils, which was estimated to be around €550 million in 2018 at the end of the project, is increasing by 30% annually.

The project contributed to the EU’s ‘European Strategy for Smart, Sustainable and Inclusive Growth, 2010’, among other key European environmental policies.

Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).