Electronically or photonically functionalized surfaces, three-dimensionally on every possible object - that is printed electronics for you. At the International Exhibition and Conference for Printed Electronics, LOPEC 2014, leading manufacturers present their latest developments in equipment technology and innovative materials. The trade show highlights clearly show that organic and printed electronics are making strides into new mass markets.
New solutions are being created based on the development of conventional fields: By combining high-tech solutions with conventional printing processes, the fledgling industry of organic electronics is opening the way to interesting future markets. "We have great expectations for our current models of CeraPrinter systems as well as the Inkjet Development Software CeraSlice", says Nicolas Bernardin, CeraPrinter Product Manager at Ceradrop, about his company's main focus at LOPEC. For its CeraPrinter Inkjet Printers, which print to an accuracy of 3 μm or 5 μm, depending on the model, suitable print heads are available from Konica Minolta or FUJIFILM Dimatix, for example, for applying various types of ink. The proprietary CAD/CAM software CeraSlice enables users to define the circuits to be printed, and output processable printer scripts.
Electronics that materialize out of thin air is what Optomec promises with its novel Aerosol Jet technology: "The Aerosol Jet technology was designed from the outset so that it can handle many materials normally used in the electronics industry", says Mike O'Reilly, Director of Product Commercialization at Optomec. The American manufacturer with its registered office based in Albuquerque (New Mexico) is a first-time exhibitor at LOPEC. Patterned layers are applied in a contactless and maskless process onto flat and three-dimensional substrates. In contrast to similar patterning technologies such as inkjet printing, the Aerosol Jet technology enables processing of solutions and dispersions with a much greater range of viscosity and reaches minimum feature sizes of 10 μm.
PST Sensors implements innovative ideas for smart temperature sensors: At LOPEC, the South African start-up will demonstrate custom-developed applications with its extremely flexible temperature systems covering a wide temperature range. These include TiM (thermal imaging mat), a thermal imager printed on paper, i.e. a beer mat which indicates the temperature, as well as a room thermometer printed on a picture of a tiger's head. In addition the company, which is also a first-time LOPEC exhibitor, is showing individual sensors and sensor arrays, such as an X-Y addressable array with 256 elements, and the sensor which is used in NASA's "printed spacecraft" and at Xerox PARC. PST Sensors' product portfolio concentrates on NTC (negative temperature coefficient) thermistors made of silicon nanoparticles that can be printed onto any materials including paper, textiles and polymer films with a wide range of form factors.
Henkel is presenting its extensive portfolio of materials for printed electronics, focusing on silver conductive pastes and electrically conductive carbon pastes. According to Ralph Mandel, Senior Account Manager Adhesive Technologies at Henkel, the global player supplies tailor-made solutions as well as many standard products. "Our motivation for exhibiting at LOPEC was mainly to enable users to develop interesting applications with our tailor-made solutions going beyond the usual standards", Mandel explains the Netherlands-based Henkel division's first appearance at the international leading trade show for printed electronics. One of the key areas of Henkel's attendance at LOPEC is printing pastes based on the use of nano-silver particles which enable optical transparency. Thus they can be used for various applications such as industrial touch screens, solar cells, electroluminescent (EL) lighting systems and micro- LED lighting. Indium tin oxide (ITO) is often used for these purposes, which sometimes involves a time-consuming and expensive production process. Nanosilver pastes, on the other hand, are easily reproducible in standardized printing processes and are therefore inexpensive to process in large quantities.
Precise systems for a wide range of applications
Innovations in plant engineering are on show too: At this year's LOPEC, Kroenert is exhibiting a coating module with a combination of slot die technology and gravure roller coating. With this combination, users are offered a high degree of flexibility for coating processes, as Frank Schaefer, Sales Director at Kroenert, emphasizes. The extremely thin layer thicknesses needed for the production of organic solar cells place very high demands on the coating accuracy in the longitudinal and transverse direction.
With its new "Test Solution" product range, Coatema is showing coating, printing and laminating on the smallest scale - both for piece goods and roll-to-roll. Laboratory systems can be customized with different printing and coating systems (slot die, knife, flexo and gravure roll). The company's collaboration with start-up LUNOVU is also one of the topics at the show: both companies are working to advance the technology of laser patterning for the roll-to-roll process rapidly.
Bosch Rexroth offers a wide range of automation solutions for reliable and economical production of organic electronics: a challenging feature of organic electronics is the vacuum sector for vapor deposition or sealing of materials. For example, displays need to be positioned particle-free in a high vacuum and substrate carriers moved independently or in synchronization. The Linear Motion System (LMS) from Rexroth drives any number of substrate carriers purely magnetically, according to the principle of an inverse linear motor, and therefore contactless. All electrical components are mounted outside the process chambers and require no physical connection with the carriers. This eliminates all sources of unwanted particulate emissions and the system increases process safety. This is confirmed by practical experience in the production of LED and OLED displays. The LMS not only works extremely cleanly, but also highly flexibly. The NYCe 4000 motion control system positions the carriers, both individually and independently from each other as well as in coordinated operations. Due to the contactless drive principle and the matching motion control system, the LMS simplifies the construction of processing equipment and allows rapid changeover to new products.
Tailor-made functionalization of surfaces
At the Fraunhofer Institute for Manufacturing Technology and Applied Materials Research IFAM in Bremen, researchers manufacture electronic components and sensors using different printing processes. In order to automate production of flat and three-dimensional components with printed electronics, the scientists at IFAM have set up a robotic production line which combines multiple printing methods at the same time: screen, inkjet, dispensing and aerosol jet printing are integrated as modules into the production unit. "With the new production line, we can combine the most diverse materials and manufacture products to customer specifications," explains Dr. Volker Zöllmer, Head of Department at Fraunhofer IFAM. In principle, components are endowed with completely new features - so a sheet of glass can measure heat with an integrated temperature sensor. Printed sensors can also be used for component monitoring, to detect cracks and damage at an early stage. For example, aerosol-printed strain gauges can detect material fatigue at an early stage in aluminum surfaces of car body parts. At LOPEC, several exhibits will be on display, including a cylinder functionalized with sensor structures.
"We look forward to showing various practical applications and examples of customer projects. Printed electronics has advantages and brings value to our customers", says Dr. Wolfgang Clemens, Head of the Applications Department at PolyIC about LOPEC. PolyIC develops and markets products based on the 'printed electronics' platform technology: The company supplies products in the fields of ‘touch sensors & passive devices’ and ‘printed electronics & displays'. All these products are based on transparent and conductive PolyTC films, which have now reached market maturity. For example, touch sensors offer transparent, conductive, and flexible options for touch screens and capacitive keys of all kinds. In addition, this technology also allows other flexible conductive structures to be implemented as passive components in many applications.