Eight innovations from Productronica

Cold-active plasma coating
MUNICH, Germany — After four rather quiet days, the world's largest trade fair focusing on electronics production ended Friday (November 13) with a weak summary: The 28.000 visitors registered at the Productronica fairground in Munich were significantly less than the past event in pre-crisis year 2007. Nevertheless, there were some remarkable innovations to see at the exhibition.

While not all represent spectacular breakthroughs, they help to keep costs at bay, speed cycle times or enable engineers to realize designs that hitherto were not possible. EE Times lists some of them.

• Cold plasma coating

A cleaning and activating process for silicon wafers as well as a wide range of other materials, cold plasma coating helps driving costs down while at the same time it avoids thermal stress to the material. Cleaning and activating are preparing steps for many succeeding processes such as bonding, casting, printing or foaming. Another application for plasma coating is the deposition of semiconducting, metal and polymer layers on a very broad range of substrates — even on temperature sensitive ones such as paper.

The "cold-active" process developed by Reinhausen Plasma GmbH (Regensburg, Germany) takes place at normal ambient pressure, doing away with reactors, pumps and lock systems and thus speeding up the cycle times. Implemented in production machines such as its Plasmabrush or Plasmadust, the process can be used for deposition of conductive paths directly onto the board, deposition of metal layers and contacts on solar wafers, or deposition of thin shielding layers on cables for electromagnetic shielding.

With its cold-active plasma method, Reinhausen Plasma already has found a customer in the semiconductor industry. According to the Reinhausen Plasma CEO Michael Bisges, the unnamed chip manufacturer was able to reduce the costs for the respective process step by a factor of 40 to 1.

• Thermoelectric generator

Startup company O-Flexx Technologies GmbH (Duisburg, Germany) has announced a concept to use Reinhausen Plasma's cold-active coating process to produce thin-film thermo-electric generators (TEGs).

TEGs are p-n junctions generating electric energy through temperature differences, making use of the so called Seebeck effect. Hitherto, these devices have been expensive since they require rare and cost-intensive materials and they are difficult to manufacture. Another weak point is their low effectiveness of only 1 to 2 percent. In an industrial scale, TEGs are used to regain electric energy from the hot exhaust pipes in cars. "Currently more or less every major OEM is evaluating this technology," revealed O-Flexx Chief Technology Officer Gerhard Span.

At Productronica, O-Flexx described TEG prototypes made of BiTe as active material. These TEGs could be used in solar heat applications where the electricity generated could help to bridge sunless days by exploiting residual heat. The company currently is developing an integrated manufacturing process in which the Plasmadust technology would help to drive production costs down.