Details
| Original language | English |
|---|---|
| Title of host publication | Laser-Based Micro- and Nanopackaging and Assembly VI |
| Publication status | Published - 20 Feb 2012 |
| Externally published | Yes |
| Event | Laser-Based Micro- and Nanopackaging and Assembly VI - San Francisco, CA, United States Duration: 24 Jan 2012 → 26 Jan 2012 |
Publication series
| Name | Proceedings of SPIE - The International Society for Optical Engineering |
|---|---|
| Volume | 8244 |
| ISSN (Print) | 0277-786X |
Abstract
Ultrashort pulsed lasers are increasingly used in micromachining applications. Their short pulse lengths lead to well defined thresholds for the onset of material ablation and to the formation of only very small heat affected zones, which can be practically neglected in the majority of cases. Structure sizes down to the sub-micron range are possible in almost all materials - including heat sensitive materials. Ultrashort pulse laser ablation - even though called "cold ablation" - in fact is a heat driven process. Ablation takes place after a strong and fast temperature increase carrying away most of the heat with the ablated particles. This type of heat convection is not possible when reducing the laser fluence slightly below the ablation threshold. In this case temperature decreases slower giving rise to heat-induced material deformations and melt dynamics. After cooling down protruding structures can remain - ablation-free laser surface structuring is possible. Structure formation is boosted on thin metal films and offers best reproducibility and broadest processing windows for metals with high ductility and weak electron phonon coupling strength. All approaches to understand the process formation are currently based only on images of the final structures. The pump-probe imaging investigations presented here lead to a better process understanding.
Keywords
- Heat-induced structures, Melt dynamics, Microbump, Nanojet, Pump-probe, Ultrashort pulse laser
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Computer Science(all)
- Computer Science Applications
- Mathematics(all)
- Applied Mathematics
- Engineering(all)
- Electrical and Electronic Engineering
Cite this
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- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
Laser-Based Micro- and Nanopackaging and Assembly VI. 2012. 824408 (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8244).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Heat-induced structure formation in metal films generated by single ultrashort laser pulses
AU - Koch, Jürgen
AU - Unger, Claudia
AU - Chichkov, Boris N.
PY - 2012/2/20
Y1 - 2012/2/20
N2 - Ultrashort pulsed lasers are increasingly used in micromachining applications. Their short pulse lengths lead to well defined thresholds for the onset of material ablation and to the formation of only very small heat affected zones, which can be practically neglected in the majority of cases. Structure sizes down to the sub-micron range are possible in almost all materials - including heat sensitive materials. Ultrashort pulse laser ablation - even though called "cold ablation" - in fact is a heat driven process. Ablation takes place after a strong and fast temperature increase carrying away most of the heat with the ablated particles. This type of heat convection is not possible when reducing the laser fluence slightly below the ablation threshold. In this case temperature decreases slower giving rise to heat-induced material deformations and melt dynamics. After cooling down protruding structures can remain - ablation-free laser surface structuring is possible. Structure formation is boosted on thin metal films and offers best reproducibility and broadest processing windows for metals with high ductility and weak electron phonon coupling strength. All approaches to understand the process formation are currently based only on images of the final structures. The pump-probe imaging investigations presented here lead to a better process understanding.
AB - Ultrashort pulsed lasers are increasingly used in micromachining applications. Their short pulse lengths lead to well defined thresholds for the onset of material ablation and to the formation of only very small heat affected zones, which can be practically neglected in the majority of cases. Structure sizes down to the sub-micron range are possible in almost all materials - including heat sensitive materials. Ultrashort pulse laser ablation - even though called "cold ablation" - in fact is a heat driven process. Ablation takes place after a strong and fast temperature increase carrying away most of the heat with the ablated particles. This type of heat convection is not possible when reducing the laser fluence slightly below the ablation threshold. In this case temperature decreases slower giving rise to heat-induced material deformations and melt dynamics. After cooling down protruding structures can remain - ablation-free laser surface structuring is possible. Structure formation is boosted on thin metal films and offers best reproducibility and broadest processing windows for metals with high ductility and weak electron phonon coupling strength. All approaches to understand the process formation are currently based only on images of the final structures. The pump-probe imaging investigations presented here lead to a better process understanding.
KW - Heat-induced structures
KW - Melt dynamics
KW - Microbump
KW - Nanojet
KW - Pump-probe
KW - Ultrashort pulse laser
UR - http://www.scopus.com/inward/record.url?scp=84858680294&partnerID=8YFLogxK
U2 - 10.1117/12.908561
DO - 10.1117/12.908561
M3 - Conference contribution
AN - SCOPUS:84858680294
SN - 9780819488879
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Laser-Based Micro- and Nanopackaging and Assembly VI
T2 - Laser-Based Micro- and Nanopackaging and Assembly VI
Y2 - 24 January 2012 through 26 January 2012
ER -