Micromachining
While machining small objects, the adverse thermal effects are felt much stronger. The material removal mechanism of CW and nanosecond fiber lasers is mainly based on melting and vaporization. In this time scale, large amount of heat conduction takes place leading large HAZ (heat affected zone) formation and degrading the machining quality. For this reason, ultrafast fiber lasers with high beam quality should be used in micromachining. The main interaction mechanism of ultrafast (<10 ps) pulses with the material is ablation in which the material absorbs the pulse energy in a very short time scale, turns into plasma state and is ejected away before heat conduction could take place. When an ultrafast pulse is focused on a small point, the photon density becomes so large that it allows multi-photon absorption process and machining virtually any materials including metals, semiconductors, polymers, ceramics and glasses.
Micro cutting & scribing applications require fine precision, small kerf width, high edge quality and minimal HAZ (heat affected zone). Generally, ultrafast fiber lasers are adequate for cutting virtually any materials (metal, semiconductor, polymer, ceramic, glass). However, green nanosecond fiber lasers may give better results for some polymer based materials. Scribing is a special case of cutting where the cut is blind and generally used in electronics in order to seperate dies on a wafer. 10x faster scribing is possible with UV nanosecond fiber lasers compared to conventional techniques.
Lasers are inevitable tools when it comes to drilling of micron sized holes/nozzles where the conventional techniques fail. Generally two types of lasers are being used for this purpose. Ultrafast fiber lasers operating at 1 µm region and excimer lasers operating at UV region. In addition to ultrafast fiber lasers, Fiblas also offers UV nanosecond fiber lasers as replacements of excimer lasers which utilize 4th & 5th harmonic generation by nonlinear crystals.
Ultrafine marking & engraving are generally used for identification, part numbering and traceability purposes. Sometimes these are desired to be microscopic, invisible to the naked eye which requires high precision machining. Although UV nanosecond fiber lasers are suitable for this purpose, ultrafast fiber lasers may be prefered since they also allow sub-surface marking.
Thanks to multi-photon absorption process, ultrafast fiber lasers are capable of processing any transparent materials with ease. Unlike excimer lasers which can only be used for surface processing (cutting/engraving), they can process inside of bulk transparent materials allowing many applications like marking, waveguide generation, fiber Bragg grating manufacturing, microfluidic channel formation.
By carefully selecting the laser parameters, it is possible to create patterns or remove coatings without damaging the underlying substrate. Especially in electronics, the current paths can be defined by this way which requires high precision in combination with an adjustable laser source (wavelength, intensity, pulse energy/duration). Fiblas offers suitable ultrafast fiber lasers as well as UV nanosecond fiber lasers for these type of applications.