Greener metal patterning method has cross sector potential

Every electronic device needs to connect its components with conductive pathways. For most, the answer is to form the appropriate pattern in metal, either by selectively removing metal from a film or printing with metal inks onto an insulating substrate. Both techniques have drawbacks, however: metal inks are expensive and removing material to make a pattern requires etching using hazardous chemicals.

Tackling this problem, a team of chemists from the University of Warwick has devised a method using no toxic chemicals and avoiding metal wastage. Moreover, the technique, which they describe in Materials Horizons, is compatible with continuous roll-to-roll processing methods and therefore suitable for mass production.

Ross Hatton and Sylvia Varagnolo received funding from the EPSRC for their project, which is based on their discovery that silver and copper, the most widely-used metals for this application, do not condense onto extremely thin films of certain highly-fluorinated compounds when the metal is deposited by simple thermal deposition, the technique used to deposit films of metal on plastic used to make crisp packets. The organofluorine compounds are similar to those used to make nonstick coatings on cookware, and so are readily available, and only tiny amounts are needed to be effective.