TY - GEN
T1 - High-resolution imaging of ejection dynamics in laser-induced forward transfer
AU - Pohl, Ralph
AU - Visser, C.W.
AU - Römer, Gerardus Richardus, Bernardus, Engelina
AU - Sun, C.
AU - Huis in 't Veld, Bert
AU - Lohse, Detlef
N1 - Joint Session with Conferences 8967 and 8970
PY - 2014/2/4
Y1 - 2014/2/4
N2 - Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental imaging study on the ejection process of gold-based LIFT. The LIFT experiments were performed using a 6.7 picosecond Yb:YAG laser source equipped with a SHG. The beam was focused onto a 200 nm thick gold donor layer. The high magnification images were obtained using bright field illumination by a 6 ns pulsed Nd:YAG laser source and a 50× long-distance microscope objective that was combined with a 200 mm tube lens. For laser fluence levels up to two times the donor-transfer-threshold, the ejection of a single droplet was observed. The typical droplet radius was estimated to be less than 3 μm. A transition of ejection features towards higher fluence, indicates a second fluence-regime in the ejection process. For higher laser fluence, the formation of an elongated gold jet was observed. This jet fragments into multiple relatively small droplets, resulting in a spray of particles on the receiving substrate. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
AB - Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental imaging study on the ejection process of gold-based LIFT. The LIFT experiments were performed using a 6.7 picosecond Yb:YAG laser source equipped with a SHG. The beam was focused onto a 200 nm thick gold donor layer. The high magnification images were obtained using bright field illumination by a 6 ns pulsed Nd:YAG laser source and a 50× long-distance microscope objective that was combined with a 200 mm tube lens. For laser fluence levels up to two times the donor-transfer-threshold, the ejection of a single droplet was observed. The typical droplet radius was estimated to be less than 3 μm. A transition of ejection features towards higher fluence, indicates a second fluence-regime in the ejection process. For higher laser fluence, the formation of an elongated gold jet was observed. This jet fragments into multiple relatively small droplets, resulting in a spray of particles on the receiving substrate. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
KW - METIS-304373
KW - IR-91602
U2 - 10.1117/12.2037231
DO - 10.1117/12.2037231
M3 - Conference contribution
T3 - Proceedings of SPIE - the international society for optical engineering
SP - -
BT - Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX
A2 - Nakata, Yoshiki
A2 - Xianfan, Xianfan
A2 - Roth, Stephan
A2 - Neuenschwander, Beat
PB - SPIE
CY - San Francisco, CA, USA
T2 - Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX, San Francisco, February 01, 2014
Y2 - 1 February 2014 through 6 February 2014
ER -