rus
The SEMICON Europa 2015, which was held in Dresden from 6 to 8 October, was the major event of the past year for the European semiconductor industry. The forum was attended by about 5 thousand professionals. Russian participants were among 360 exhibitors, in particular, enterprises of Innovative territorial cluster Zelenograd.
Business program of the exhibition included more than 70 events and about 250 reports. A special section of the program was devoted to flexible (plastic) electronics, and we will focus attention in this review on this subject.
The main theme of the conference Plastic Electronics 2015 is the development of Internet of Everything (IoE), a new stage of evolution of the Internet as a universal communication system. New polymer-based components create the technological basis for IoE. These components allow to create a compact, flexible and relatively inexpensive multifunction electronic devices for the consumer market, as well as for health care and industry.
Technologies and equipment
Christopher Bower, Chief Technology Officer at X-Celeprint Inc. told about the new features of the micro assembly through the integration of ultra-miniature inorganic semiconductor devices onto substrates of different nature. Micro transfer printing technology (µTP) can be used in the production of new form factors of optical components, magnetic storage devices, displays, photovoltaic and bio-integrated electronics, providing a combination of high performance and cost benefits.
Stergios Logothetidis from the Lab for Thin Films, Nanosystems & Nanometrology (LTFN) of Aristotle University of Thessaloniki (Greece) spoke about the possibilities of use of ultrafast laser patterning techniques in the R2R processes for the manufacture of organic photovoltaics and other flexible electronics devices. Laser processes offer greater resolution than the printing technology, allowing to increase the efficiency of functional structures. LTFN implements in-line laser scribing method for patterning of organic and inorganic nanomaterials of flexible electronics, such as indium tin oxide, PEDOT:PSS, polythiophenes and fullerene derivatives.
Dimitris Karnakis, technical manager of R&D projects at Oxford Lasers Ltd, also dedicated his presentation to laser technology, namely, the use of diode-pumped solid state (DPSS) lasers. Laser treatment is a simple and cost effective alternative to traditional printing technologies in the production of flexible electronics. It is characterized by high resolution and direct imaging or processing. Laser systems can be easily reconfigured and are scalable. In particular, for prototyping or serial production such techniques as laser-induced forward transfer (LIFT) printing, selective laser sintering of conductive inks, selective thin-film patterning of multi-layered stacks laser surface functionalization could be widely adopted. All of these technologies are highly effective for processing of rigid and flexible materials. Despite the extensive studies practical problems remain, such as edge effect (delamination) or non-uniform spatial temperature gradients in sintering, which affects repeatability of processes.
Jacques Kools, CEO at Encapsulix (France), has introduced high-performance equipment for atomic layer deposition (ALD) and developments in the field of encapsulation of organic light emitting diodes. He noted that ALD has good prospects in organic electronics production, however, its effective use to deliver low temperature processes (less than 100°C), high throughput processing and acceptable cost of ownership. Encapsulix has developed the PPW (Parallel Precursor Wave) reactor architecture that meets the listed requirements. In particular, the deposition rate compared to conventional systems is increased 20 times or more.
Jürgen Kreis, director business development at Aixtron (Germany), presented the technologies of thin-film deposition OVPD and OPTACAP for the production of organic light emitting diodes. OVPD is organic vapor phase deposition, based on use of inert carrier-gas for the deposition of organic stacks. The technology is developed by prof. S.Forrest at Princeton University. OPTACAP process is developed to obtain barrier films of silicon nitride by the plasma enhanced chemical vapor deposition (PECVD).
Materials
Philippe Guaino, project leader at CRM Group (Belgium), devoted his report to the production of organic electronics and printing of "smart" systems on steel substrates. He noted that devices based on plastic films, paper and thin glass "foils" are characterized by low durability, poor heat dissipation and barrier properties. In this context, an interesting alternative may be a metal foil. CRM Group has developed for the production of organic electronics steel substrate, which may have required customer mechanical rigidity. The steel has good barrier properties to oxygen and water and perfectly dissipates heat, improving the lifetime of equipment. The device on the steel base are of interest for applications in difficult and extreme conditions. Thus, the new material is compatible with the roll to roll (R2R) process.
Stefan Mogck, department manager at Fraunhofer FEP, has noted good prospects for the use of glass in the manufacture of organic light emitting diodes. The glass has a good barrier qualities, resistance to high temperatures and surface smoothness, so the Fraunhofer FEP develops ultra-thin and flexible glass materials, compatible with sheet-to-sheet and roll-to-roll production processes. To prevent breakage of the ultra-thin glass with a thickness of 50 to 100 μm, it is pro-posed to laminate it on the PET-film. One of the problems of the R2R technology is to minimize the residual moisture in the film. Thin laminate on glass substrates do not require extensive drying, which increases the stability of the process.
Quality control
Argiris Laskarakis, head of organic electronics group at the LTFN of Aristotle University of Thessaloniki, presented a new method of in-line quality control for R2R technology. Development is focused primarily on the production of organic photovoltaics for the optimization of the blend morphology of the photoactive layer. It is proposed to use optical methods of quality control such as in-line spectroscopic ellipsometry and Raman spectroscopy with sophisticated modelling procedures. According to the speaker, these methods are effective for polythiophenes, fullerene derivatives and other materials of the photoactive thin-film coatings and allow to automate the quality control of organic electronics production.
Eric Novak, director of bus. dev. at 4D Technology, has introduced a compact 3D Metrology module for control of materials and devices of flexible electronics. The measurements are performed with sub-nanometer vertical and micrometer lateral resolution for accurate roughness and defect height determination. The device is designed for online measurements in R2R systems. Substrates moving at up to 3 m/min may be measured with 2 micrometer resolution. The modules can work in vacuum conditions and are equipped with vibration protection.
Business program of the exhibition included more than 70 events and about 250 reports. A special section of the program was devoted to flexible (plastic) electronics, and we will focus attention in this review on this subject.
The main theme of the conference Plastic Electronics 2015 is the development of Internet of Everything (IoE), a new stage of evolution of the Internet as a universal communication system. New polymer-based components create the technological basis for IoE. These components allow to create a compact, flexible and relatively inexpensive multifunction electronic devices for the consumer market, as well as for health care and industry.
Technologies and equipment
Christopher Bower, Chief Technology Officer at X-Celeprint Inc. told about the new features of the micro assembly through the integration of ultra-miniature inorganic semiconductor devices onto substrates of different nature. Micro transfer printing technology (µTP) can be used in the production of new form factors of optical components, magnetic storage devices, displays, photovoltaic and bio-integrated electronics, providing a combination of high performance and cost benefits.
Stergios Logothetidis from the Lab for Thin Films, Nanosystems & Nanometrology (LTFN) of Aristotle University of Thessaloniki (Greece) spoke about the possibilities of use of ultrafast laser patterning techniques in the R2R processes for the manufacture of organic photovoltaics and other flexible electronics devices. Laser processes offer greater resolution than the printing technology, allowing to increase the efficiency of functional structures. LTFN implements in-line laser scribing method for patterning of organic and inorganic nanomaterials of flexible electronics, such as indium tin oxide, PEDOT:PSS, polythiophenes and fullerene derivatives.
Dimitris Karnakis, technical manager of R&D projects at Oxford Lasers Ltd, also dedicated his presentation to laser technology, namely, the use of diode-pumped solid state (DPSS) lasers. Laser treatment is a simple and cost effective alternative to traditional printing technologies in the production of flexible electronics. It is characterized by high resolution and direct imaging or processing. Laser systems can be easily reconfigured and are scalable. In particular, for prototyping or serial production such techniques as laser-induced forward transfer (LIFT) printing, selective laser sintering of conductive inks, selective thin-film patterning of multi-layered stacks laser surface functionalization could be widely adopted. All of these technologies are highly effective for processing of rigid and flexible materials. Despite the extensive studies practical problems remain, such as edge effect (delamination) or non-uniform spatial temperature gradients in sintering, which affects repeatability of processes.
Jacques Kools, CEO at Encapsulix (France), has introduced high-performance equipment for atomic layer deposition (ALD) and developments in the field of encapsulation of organic light emitting diodes. He noted that ALD has good prospects in organic electronics production, however, its effective use to deliver low temperature processes (less than 100°C), high throughput processing and acceptable cost of ownership. Encapsulix has developed the PPW (Parallel Precursor Wave) reactor architecture that meets the listed requirements. In particular, the deposition rate compared to conventional systems is increased 20 times or more.
Jürgen Kreis, director business development at Aixtron (Germany), presented the technologies of thin-film deposition OVPD and OPTACAP for the production of organic light emitting diodes. OVPD is organic vapor phase deposition, based on use of inert carrier-gas for the deposition of organic stacks. The technology is developed by prof. S.Forrest at Princeton University. OPTACAP process is developed to obtain barrier films of silicon nitride by the plasma enhanced chemical vapor deposition (PECVD).
Materials
Philippe Guaino, project leader at CRM Group (Belgium), devoted his report to the production of organic electronics and printing of "smart" systems on steel substrates. He noted that devices based on plastic films, paper and thin glass "foils" are characterized by low durability, poor heat dissipation and barrier properties. In this context, an interesting alternative may be a metal foil. CRM Group has developed for the production of organic electronics steel substrate, which may have required customer mechanical rigidity. The steel has good barrier properties to oxygen and water and perfectly dissipates heat, improving the lifetime of equipment. The device on the steel base are of interest for applications in difficult and extreme conditions. Thus, the new material is compatible with the roll to roll (R2R) process.
Stefan Mogck, department manager at Fraunhofer FEP, has noted good prospects for the use of glass in the manufacture of organic light emitting diodes. The glass has a good barrier qualities, resistance to high temperatures and surface smoothness, so the Fraunhofer FEP develops ultra-thin and flexible glass materials, compatible with sheet-to-sheet and roll-to-roll production processes. To prevent breakage of the ultra-thin glass with a thickness of 50 to 100 μm, it is pro-posed to laminate it on the PET-film. One of the problems of the R2R technology is to minimize the residual moisture in the film. Thin laminate on glass substrates do not require extensive drying, which increases the stability of the process.
Quality control
Argiris Laskarakis, head of organic electronics group at the LTFN of Aristotle University of Thessaloniki, presented a new method of in-line quality control for R2R technology. Development is focused primarily on the production of organic photovoltaics for the optimization of the blend morphology of the photoactive layer. It is proposed to use optical methods of quality control such as in-line spectroscopic ellipsometry and Raman spectroscopy with sophisticated modelling procedures. According to the speaker, these methods are effective for polythiophenes, fullerene derivatives and other materials of the photoactive thin-film coatings and allow to automate the quality control of organic electronics production.
Eric Novak, director of bus. dev. at 4D Technology, has introduced a compact 3D Metrology module for control of materials and devices of flexible electronics. The measurements are performed with sub-nanometer vertical and micrometer lateral resolution for accurate roughness and defect height determination. The device is designed for online measurements in R2R systems. Substrates moving at up to 3 m/min may be measured with 2 micrometer resolution. The modules can work in vacuum conditions and are equipped with vibration protection.
Readers feedback
