Nouvelles applications des lasers ultra-rapides : patterning de composants OLED par ablation laser et mise en forme de faisceau.

Oxford Lasers was founded in 1977 to exploit new laser technologies. The company has
been in the field of laser micromachining for over 20 years. Oxford Lasers offers subcontract
laser micromachining services, contract research and development and laser micromachining
systems for Universities, Research Institutes and Industrial companies. The company
operates in many markets including microelectronics, solar, healthcare, automotive,
biomedical etc.

Oxford Lasers operate in the area of high precision, high accuracy, laser micromachining
employing nanosecond, picosecond and femtosecond lasers in the infrared through the deep
ultraviolet region of the spectrum. This allows high precision drilling, milling, cutting and
marking in materials from metals and ceramics through to polymers and glasses.

During its presentation, Oxford Lasers will introduce two technological innovations in two
recent areas of significant interest to Industrial Users and show their results.

a) Laser Ablation for OLED Patterning
Lasers have already become a key technology for micro and nano-engineering providing
high-resolution, accuracy, speed and flexibility. Their unique properties have been
successfully exploited so far in microfabrication to meet the consumer fuelled demand for
miniaturisation. They have enabled the technical and commercial success of many massproduced
components ranging from photovoltaic cells and inkjet print heads to flat panel
displays, telecom Bragg gratings, MEMS components and disposable medical diagnostics.
Oxford Lasers through its participation in the large scale EU-funded Fast2Light program has
developed and will present novel laser ablation techniques for the selective removal of
ultrathin layers in a multilayered OLED stack on foil. The advantage of our technology is that
it can enable selective patterning of functional OLED layers without any damage to
neighbouring or underlying layers in an OLED stack. This paves the way for rapid, low cost
and efficient layer patterning in large area roll-to-roll OLED manufacturing.

b) High Throughput Precision Parallel Laser Micro-Processing
Ultrafast laser microstructuring provides unique manufacturing advantages being clearly
deterministic, highly reproducible and inherently precise. By utilising the very high laser
repetition rates (PRF) available from modern ultrafast lasers (up to MHz), production
throughput can be maximised. However many commercially available laser sources already
offer enough output (several tens of μJ/pulse) well in excess of typical requirements for
single-beam high precision machining in certain industrial applications. Subsequent laser
attenuation during process optimisation cancels the PRF advantage, reducing efficiency and
resulting in energy waste and unnecessary costs. Recent results that employ parallel laser
processing to overcome this problem are presented - offering a versatile beam shaping
solution by combining liquid crystal on silicon reflective spatial light modulators (LCoS-SLM)
with ultrafast lasers. An SLM is a dynamic diffractive optical element that can linearly
modulate the phase of an incoming wavefront with high efficiency by applying a computer
generated hologram to transform the incident beam intensity distribution into any desirable
pattern for micromanipulation. For example, by splitting an energetic ultrafast laser beam into
many lower energy beamlets, each capable of individual precision micro-structuring, one can
demonstrate typically tenfold throughput gain or higher depending on material. The
dynamically addressable SLM device permits frequent pattern changes (millisecond scale
refresh rate) easily implemented via a user-friendly pc interface
Potential applications to benefit from this approach could be found in photovoltaics, plastic
electronics, medical device and microelectronics manufacturing among other high volume
applications.

C. Bansal et A. Ferguson

OXFORD LASERS

Téléphone : +44 (0) 1235 814433
Fax : +44 (0) 1235 810060
E-mail : alan.ferguson@oxfordlasers.com