Other materials

Ceramics crack, semiconductors chip and organic materials char, each under a different kind of thermal load. Femtosecond laser pulses are over before heat leaves the focal volume, so ceramic is milled, silicon and GaAs wafers are cut clean, organics are machined without burnt edges, and dielectric surfaces are activated for metallization.

Material processing
Material processing Glass Metal Polymer Other materials
Other materials

Ceramic processing with GHz burst

Femtosecond lasers are highly effective for processing ceramics and offer higher precision than traditional mechanical methods. However, they often fall short in throughput. The processing rate can be increased by raising the repetition rate, splitting the beam, or enlarging the spot size. Another approach is the use of GHz bursts: trains of femtosecond pulses with intra-burst repetition rates in the GHz range. A burst splits a single high-energy pulse into multiple smaller pulses, which makes fuller use of the laser power and increases the processing throughput.

FemtoLux with its GHz burst option was used to study the influence of MHz and GHz bursts on the processing of alumina ceramics. Squares of 1×1 mm² were milled in different burst modes, and the removed volumes were measured with an optical 3D profilometer. With 92 pulses per burst in GHz mode, the process throughput increased from 6.39 mm³/min (single-pulse mode) to 10.38 mm³/min.

Optical 3D profilometer image of milled alumina squares in different operational modes.

Optical 3D profilometer image of milled alumina squares in different operational modes.

Recommended products

FemtoLux
Industrial Femtosecond Lasers
  • 50 W / >300 µJ at 1030 nm
  • 20 W / >50 µJ at 515 nm
  • 10 W / >25 µJ at 343 nm
  • < 400 fs – 1 ps
  • Single shot to 4 MHz (AOM controlled)
  • MHz, GHz, MHz+GHz burst modes

Similar applications

50 µm depth groove formation in ceramic.
Femtosecond laser formation of grooves in ceramic

Ceramic is hard and brittle: mechanical processing presses on it with large forces and can crack the substrate. Femtosecond laser pulses form grooves without mechanical contact. Grooves 30, 50 and 70 µm deep were scribed at speeds up to 44.1 mm/s, and the 343 nm wavelength reduced the heat-affected zone from 8.23 µm to 4.88 µm.
SEM image of a trench milled in GaAs under a layer of water.
Femtosecond processing of GaAs in air and water

Milling GaAs in ambient air leaves a band of debris redeposited along the trench walls. Under a layer of water the same process cuts deeper and cleaner: trench depth rose from 58 µm to 105 µm and the redeposition band shrank from 34 µm to 7.6 µm. Ablation efficiency was higher in all three regimes tested.
Cutting of FZ-Si wafer.
Femtosecond laser cutting of FZ-Si wafer

Mechanical dicing follows silicon’s crystallographic cleave planes, so diced chips come out with straight edges only. Femtosecond pulses cut FZ-Si wafers along curved contours instead: a 0.4 mm float-zone wafer was cut with a low heat-affected zone and an undamaged bottom surface.
Copper circuit patterns on polyimide (PI).
Selective Surface Activation Induced by Laser (SSAIL)

SSAIL writes copper circuits directly onto dielectric surfaces: an ultra-short pulse laser draws the pattern, chemical activation follows it, and electroless plating deposits metal only on the lasered areas. Developed by FTMC and Akoneer, the process reaches trace widths down to 1 µm on PC/ABS, PMMA, PET, FR-4, Al2O3 ceramic, fused silica and silicon.
Cut edge of a heat-sensitive organic material.
Heat-sensitive organic material processing

Heat-sensitive organic materials warp and char when a cutting process leaves heat behind. Femtosecond pulses remove material before heat spreads into the lattice: thin organic sheets for medical applications were cut at 100 mm/s with 350 fs pulses, with kerf widths down to 14.38 µm and no charring on the cut edges.
All applications