Because conventional coating processes are increasingly coming up against their technological limits and are often too costly, the Fraunhofer Institute for Laser Technology ILT developed a resource-efficient process for laser-based functionalizing of nano- and microparticle materials. As well as being suitable for inline applications, this process is marked by a high degree of flexibility and energy efficiency, while also allowing gentle processing of temperature-sensitive substrates.
Whether it is transparent conductive layers, conductor paths on semiconductors, anti-reflective surfaces on displays, self-cleaning layers on highly transparent glass, or corrosion, scratch and wear protection layers on components subject to high mechanical stress: in almost every area of industrial manufacturing, there is a great need for functional layers to optimize the surface properties of all sorts of components.
Industrially established processes for the production of high-performance coatings tend to employ vacuum coating processes. But these are costly, as they require elaborate systems technology and due to the required batch processing. More affordable processes, such as electroplating or flame spraying, are either applicable only to certain classes of substrate or else display major drawbacks in terms of the layer characteristics they produce. Coating temperature-sensitive substrates is a particularly thorny challenge in this regard.
Energy-efficient coating of temperature-sensitive substrates
Scientists at Fraunhofer ILT, working with industry partners, have succeeded in developing a resource-efficient laser-based surface functionalization process. This process combines wet-chemical coating processes with a laser process for subsequent functionalizing of the applied material. For example, when coating a glass, plastic or semiconductor substrate, an indium tin oxide (ITO)-nanodispersion is printed onto the component using an inkjet process.
Next, a galvo scanner is used to guide a focused laser beam over the surface to be processed. Laser processing significantly increases the conductivity of the ITO layer, while putting the substrate under far less thermal stress and consuming far less energy than conventional furnace-based coating processes. The new laser-based coating process enables the gentle coating of substrates with a low temperature stability and thereby widens the scope of wet-chemical coating processes significantly.
Locally selective deposition saves on material
Using conventional processes to achieve a locally selective coating of surfaces is not possible or prohibitively expensive in most cases. Functional considerations dictate that any surplus material must be subsequently removed, sometimes using elaborate processes, and this results in an enormous cost disadvantage. In contrast, the fact that laser processes can be controlled with spatial and temporal precision means they are able to functionalize coating materials in exactly the right places on the component and with no wastage.
Suitability for inline applications
A further challenge in functionalizing surfaces is how to integrate the coating process into existing production lines. Conventional processes for a thermal post-treatment (e.g. furnace-based processes) cannot be easily integrated into production lines at low costs. Fraunhofer ILT’s laser coating process poses no such problems, since the printing and laser processes it features are ideal for inline applications. This saves manufacturers a huge amount of time and money.
Fraunhofer ILT’s laser-based coating process can be tailored to meet a wide variety of coating needs. Spatial adaption to the substrate geometry is done by the precise control of the laser intensity distribution. Furthermore the application of pulsed laser beams enables the precise temporal control. Besides creating conductor paths on substrates made of glass, silicon or polymers such as polyethylene terephthalate (PET), it can for instance also be used to apply ceramic corrosion and wear protection layers of zirconium dioxide onto hardened steel. This process is of particular relevance to automotive manufacturing, in which several million components must be coated each year so they can withstand high levels of static and dynamic stress as well as extremes of temperature.
Fraunhofer ILT at Hannover Messe
Our experts will be in Hannover on the joint IVAM booth C50.13 in hall 17 of Hannover Messe from April 8-12, 2013 to present various coated exhibits that highlight the breadth of applications for thin film processing.
Dipl.-Phys. Dominik Hawelka
Group Thin Film Processing
Phone +49 241 8906-676
Dr. Jochen Stollenwerk
Head of the Group Thin Film Processing
Phone +49 241 8906-411
Fraunhofer Institute for Laser Technology ILT
52074 Aachen, Germany
Axel Bauer | Source: Fraunhofer-Institut
Further information: www.ilt.fraunhofer.de
More articles from Process Engineering:
Fraunhofer FEP introduces arcPECVD: A novel roll-to-roll PECVD process with very high coating rates
11.06.2013 | Fraunhofer-Institut für Elektronenstrahl- und Plasmatechnik FEP
Recycling Carbon Fibers from Composite Materials
06.06.2013 | Siemens AG
... two engines aircraft project “Elektro E6”.
The countdown has been started for opening the gates again for the worldwide leading aviation and space event in Le Bourget, Paris from June 17th - 23rd, 2013.
EADCO & PC-Aero will present at the Paris Air Show in Hall H4 booth F-7 their new future aircraft and innovative project: ...
Siemens scientists have developed new kinds of ceramics in which they can embed transformers.
The new development allows power supply transformers to be reduced to one fifth of their current size so that the normally separate switched-mode power supply units of light-emitting diodes can be integrated into the module's heat sink.
The new technology was developed in cooperation with industrial and research partners who ...
Cheaper clean-energy technologies could be made possible thanks to a new discovery.
Led by Raymond Schaak, a professor of chemistry at Penn State University, research team members have found that an important chemical reaction that generates hydrogen from water is effectively triggered -- or catalyzed -- by a nanoparticle composed of nickel and phosphorus, two inexpensive elements that are abundant on Earth. ...
The Fraunhofer Institute for Laser Technology ILT generated a lot of interest at the LASER World of Photonics 2013 trade fair with its numerous industrial laser technology innovations.
Its highlights included beam sources and manufacturing processes for ultrashort laser pulses as well as ways to systematically optimize machining processes using computer simulations. There was even a specialist booth at the fair dedicated to the revolutionary technological potential of digital photonic production.
Now in its fortieth year, LASER World ...
It's not reruns of "The Jetsons", but researchers working at the National Institute of Standards and Technology (NIST) have developed a new microscopy technique that uses a process similar to how an old tube television produces a picture—cathodoluminescence—to image nanoscale features.
Combining the best features of optical and scanning electron microscopy, the fast, versatile, and high-resolution technique allows scientists to view surface and subsurface features potentially as small as 10 nanometers in size.
The new microscopy technique, described in the journal AIP Advances,* uses a beam of electrons to excite a specially ...
18.06.2013 | Materials Sciences
18.06.2013 | Health and Medicine
18.06.2013 | Life Sciences
14.06.2013 | Event News
13.06.2013 | Event News
10.06.2013 | Event News