Jetting regimes of double-pulse laser-induced forward transfer

Abstract

We use the double-pulse laser-induced forward transfer (DP-LIFT) process, combining a quasi-continuous wave (QCW) and a femtosecond (fs) laser pulse to achieve jetting from a 1-µm thick copper film. The influence of the fs laser fluence on the dynamics of the liquid copper jetting is experimentally investigated by time-resolved shadowgraphy and theoretically analyzed with a simple energy balance model. Different jetting regimes are identified when varying the fs laser fluence. We demonstrate that the adjustment of this latter parameter while keeping all the others constant, allows accurate control of the diameter of the printed droplets from 1.9 µm to 6.0 µm. This leads us to a demonstration in which we print debris-free micro-pillars with an aspect ratio of 19 onto a silicon receiver substrate set as far as 60 µm away from the donor film.

Ultrafast Laser Additive Manufacturing: A Review

“…In a similar approach, Ref. [246] elucidated jetting regimes for double-pulse LIFT of copper film (Figure 24). Shadowgraphic imaging will be important for characterization of any current and future LIFT methods.…”

Direct Writing of High‐Resolution, High‐Quality Pure Metal Patterns on Smooth Transparent Substrates by Laser‐Induced Forward Transfer Followed by a Novel Laser Treatment

“…With precise tailoring of the laser fluence and process optimization, deposition of droplets with feature sizes smaller than the laser beam spot is possible, [9,19,20] making LIFT a promising candidate for printing high-resolution, high-aspect-ratio structures. For instance, successful deposition of metallic microdots, [19] lines, [1,[20][21][22] interconnects, [23][24][25] pillars, [17,26] 3D objects, and free-standing structures [1,27] has been reported. High-throughput LIFT printing of copper for the fabrication of electronic circuitry as well as 3D pure metal structures was reported.…”

Parametrization and simulation of blister-actuated laser-induced forward transfer (BA-LIFT) and LIFT for high-viscosity pastes

“…Nonetheless, a double-pulse scheme can be implemented to transfer dots from thin metallic films. The first pulse melts down the donor and the second one projects the material in a regular Liquid-State LIFT process (Li, Q., Grojo, Alloncle and Delaporte, 2019a;Li, Q., Grojo, Alloncle and Delaporte, 2019b). Metal oxides have also been successfully transferred through this technique (Papadopoulou et al, 2010).…”