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

Selective Surface Activation Induced by Laser (SSAIL)

SSAIL (Selective Surface Activation Induced by Laser) is a technology developed by the Center for Physical Sciences and Technology (FTMC) and Akoneer for writing electronic circuits directly onto dielectric surfaces. The process runs in three steps: an ultra-short-pulse laser modifies the surface along the circuit pattern, the modified areas are chemically activated, and electroless plating then deposits copper only where the laser has written. Trace widths go down to 1 µm, and the process works on PC/ABS, PMMA, PET, FR-4, Al2O3 ceramic, fused silica, silicon, and other materials.

Copper circuit patterns on polyimide (PI).

Copper circuit patterns on polyimide (PI).

Courtesy of Akoneer.

Manufacturing examples

Copper circuit patterns across a full glass wafer.

Copper circuit patterns across a full glass wafer.

Courtesy of Akoneer.

Dotted copper patterns on transparent glass.

Dotted copper patterns on transparent glass.

Courtesy of Akoneer.

LEDs mounted on SSAIL-written circuits on glass.

LEDs mounted on SSAIL-written circuits on glass.

Courtesy of Akoneer.

Copper traces on the curved surfaces of a molded 3D part.

Copper traces on the curved surfaces of a molded 3D part.

Courtesy of Akoneer.

Transparent LED display demonstrator on PA4T.

Transparent LED display demonstrator on PA4T.

Courtesy of Akoneer.

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.
Optical 3D profilometer image of milled alumina squares in different operational modes.
Ceramic processing with GHz burst

Femtosecond lasers mill ceramics precisely but slowly. GHz bursts raise the throughput: trains of pulses at GHz intra-burst repetition rates split one high-energy pulse into many smaller ones. With 92 pulses per burst, alumina milling throughput rose from 6.39 mm³/min in single-pulse mode to 10.38 mm³/min.
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.
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