| |
Electromagnetic shielding coatings for better performance of mobile telephones
Magnetron sputtering is a vacuum technology for depositing thin, metal or ceramic coatings onto plastics, metals or ceramics. Its particular advantage is the ability to deposit high quality, high conductive, copper films to protect electronic devices from electromagnetic interference. In the same process these copper films can be protected with thin stainless steel layers. Until now, process problems have limited magnetron sputtering of plastic substrates to small coating areas. The REOXCOAT project took up this challenge and successfully overcame technical hurdles to scale-up the magnetron sputtering technique. It achieved outstanding commercial results by coating small plastic parts through mass production in six new factories situated in Europe and around the world.
A challenge from the market
 By the mid-nineties, rising mobile phone use raised public awareness of the possible health hazards to users, which in turn brought the demand for improved electromagnetic shielding solutions to the fore. However, classical solutions using electroplating, painting and thermal evaporation had shown harmful environmental effects and were not well suited for the increasing production of mobile phones.
To find a solution, a newly formed Finnish SME, Surfcoat Oy, brought together a consortium to bid for co-operative research funding from the FP4 Brite-Euram programme. The research objective of the Reoxcoat project was to demonstrate technologies for industrial-scale large-area coating using magnetron sputtering.
Experts in sputtering processes at Uppsala University in Sweden, and sputtering equipment builders Teer Coatings from the UK and FHR from Germany, pooled their efforts in process and equipment development. Uppsala worked on process development and simulation; Surfcoat carried out the major tests, and FHR provided specialist knowledge in gas supply systems and target design. The Finnish SME Finnvert brought experience in DC power supplies.
Second-hand equipment for first-class results
The coating industry considered that scaling-up magnetron sputtering systems to produce economic coatings with ‘difficult' materials such as aluminium oxide could not be achieved, but the Reoxcoat results proved them wrong. The consortium refurbished a disused magnetron system and adapted it to produce large-scale high-quality coatings, including electromagnetic interference shielding coatings for mobile phones. The coating process takes place under vacuum which means virtually no pollutants are present in the workplace. Additional achievements included the development of improved targets and new gas supply and process control systems coordinated by FHR and pulsed DC power supplies from Finnvert. For the first time, all the different components – magnetrons, target design and target bonding, gas supply and control, enhanced pulsed DC power supplies, and overall process control – were optimised for large-area applications.
This breakthrough allowed significant cost savings for an electromagnetic barrier coating, bringing multiple benefits to mobile phone manufacturers and allowing much stricter limits for mobile telephone safety standards, thus reducing consumer exposure to electromagnetic radiation.
Showing fast growth
The project leader Surfcoat (now part of Savcor) was formed just before the project began by Mrs Rosa Aimo and Dr Kaj Pischow. It had two staff and began operations in a garage with a tiny budget. Seven years later, it is a large company with 1200 employees spread over six factories in Finland, Brazil, USA, China and Hungary, and with a turnover in excess of €45 million. This growth has clearly added to European expertise in this critical field of technology. The technologies developed in the project have made the company a major supplier to Nokia and other mobile phone manufacturers.
A further direct result of the Reoxcoat project is that Teer Coatings has grown from a €100 000 turnover, five-person company to one of the world's leading suppliers of large-area sputter coaters, with several patents protecting its key innovations. With a €3-4 million turnover and 50 employees, Teer is expanding continuously. Large-scale magnetron coating should also find applications in other industrial sectors which were previously prevented on cost grounds from using this superior technology.
This commercial success was greatly helped by a joint venture formed between Teer and Surfcoat after the project finished, but would not have been possible without EC support through a CRAFT project. This was followed by assistance with venture capital funding at the crucial moment to permit the explosive growth of Surfcoat and Teer. |
