Micromachines · 2020 · 52 citations · 32 references
EngineeringMaterials EngineeringMaterials ScienceDigital FabricationMechanical Behavior Of MaterialsMicrofabricationFracture MechanicsLaser CuttingLaser Material ProcessingLaser PhysicsMachiningUltrafast OpticsFemtosecond Laser ParametersFemtosecond Laser PulsesLaser Beam FocusingLaser Cut QualityLaser Cutting ParametersScan SpeedUltrafast Laser Material ProcessingUltrafast Laser Micromachining
The study presents a one‑step method for cutting 250‑µm quartz plates with 200‑fs, 1030‑nm ultrashort laser pulses. The process relies on selecting pulse repetition rate, scan speed, overlap, and energy to generate tensile stresses from relaxed compressive stresses in the focal volume, which create micro‑fractures that propagate along the beam path to cut the quartz. The study demonstrates that repetition rate, scan speed, pulse overlap, and pulse energy directly affect cutting quality.
We report on a one-step method for cutting 250-µm-thick quartz plates using highly focused ultrashort laser pulses with a duration of 200 fs and a wavelength of 1030 nm. We show that the repetition rate, the scan speed, the pulse overlap and the pulse energy directly influence the cutting process and quality. Therefore, a suitable choice of these parameters was necessary to get single-pass stealth dicing with neat and flat cut edges. The mechanism behind the stealth dicing process was ascribed to tensile stresses generated by the relaxation of the compressive stresses originated in the laser beam focal volume during irradiation in the bulk material. Such stresses produced micro-fractures whose controlled propagation along the laser beam path led to cutting of the samples.
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