Abstract
Flexible printed circuit board (FPCB), consisting of copper sheets laminated onto non conductive film substrates with multiple structures, are core elements in electronics with their flexibility and capability of high density 3 dimensional wiring characteristics. In laser applied FPCB processing, a better understanding of the ablation mechanism leads to precision control of the depth processing especially by monitoring of the material transition layer. For this purpose, here we investigate the temporal and spectral behavior of the plasma plum generated on the single sided structure of FPCB using the technique of laser induced breakdown spectroscopy (LIBS). Using KrF excimer laser, the characteristic spectral emission lines of C2 swan band at the wavelength of 516.5 nm and neutral copper at the wavelength range from 510 nm to 522 nm are acquired under ambient pressure in the ablation process of polyimide film and copper coated layer respectively. From a time delay from 50 ns to 4.05 μs from the beginning of the laser pulse, the temporal profiles of the spectral intensity are obtained in steps of 200 ns, which have a tendency of exponential decrease on both C2 and neutral copper. In particular, we concentrate our attention on the temporal intensity behavior of the Bremsstrahlung continuum emission that decides the proper set of detection time window, by which the monitoring sensitivity of LIBS is determined. Finally, using the information of the temporal analysis for each molecular, atomic, and continuum emission, the transition layer between polyimide and copper film is distinguished by their characteristic peak information.
| Original language | English |
|---|---|
| Title of host publication | Photon Processing in Microelectronics and Photonics VII |
| Volume | 6879 |
| DOIs | |
| Publication status | Published - 2008 Jun 17 |
| Event | Photon Processing in Microelectronics and Photonics VII - San Jose, CA, United States Duration: 2008 Jan 21 → 2008 Jan 24 |
Other
| Other | Photon Processing in Microelectronics and Photonics VII |
|---|---|
| Country | United States |
| City | San Jose, CA |
| Period | 08/1/21 → 08/1/24 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering
Cite this
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Temporal and spectral analysis of laser induced plasma in the ablation process of flexible printed circuit board. / Ryoo, Hoon C.; Kim, Seok; Hahn, Jae Won.
Photon Processing in Microelectronics and Photonics VII. Vol. 6879 2008. 68791N.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
TY - GEN
T1 - Temporal and spectral analysis of laser induced plasma in the ablation process of flexible printed circuit board
AU - Ryoo, Hoon C.
AU - Kim, Seok
AU - Hahn, Jae Won
PY - 2008/6/17
Y1 - 2008/6/17
N2 - Flexible printed circuit board (FPCB), consisting of copper sheets laminated onto non conductive film substrates with multiple structures, are core elements in electronics with their flexibility and capability of high density 3 dimensional wiring characteristics. In laser applied FPCB processing, a better understanding of the ablation mechanism leads to precision control of the depth processing especially by monitoring of the material transition layer. For this purpose, here we investigate the temporal and spectral behavior of the plasma plum generated on the single sided structure of FPCB using the technique of laser induced breakdown spectroscopy (LIBS). Using KrF excimer laser, the characteristic spectral emission lines of C2 swan band at the wavelength of 516.5 nm and neutral copper at the wavelength range from 510 nm to 522 nm are acquired under ambient pressure in the ablation process of polyimide film and copper coated layer respectively. From a time delay from 50 ns to 4.05 μs from the beginning of the laser pulse, the temporal profiles of the spectral intensity are obtained in steps of 200 ns, which have a tendency of exponential decrease on both C2 and neutral copper. In particular, we concentrate our attention on the temporal intensity behavior of the Bremsstrahlung continuum emission that decides the proper set of detection time window, by which the monitoring sensitivity of LIBS is determined. Finally, using the information of the temporal analysis for each molecular, atomic, and continuum emission, the transition layer between polyimide and copper film is distinguished by their characteristic peak information.
AB - Flexible printed circuit board (FPCB), consisting of copper sheets laminated onto non conductive film substrates with multiple structures, are core elements in electronics with their flexibility and capability of high density 3 dimensional wiring characteristics. In laser applied FPCB processing, a better understanding of the ablation mechanism leads to precision control of the depth processing especially by monitoring of the material transition layer. For this purpose, here we investigate the temporal and spectral behavior of the plasma plum generated on the single sided structure of FPCB using the technique of laser induced breakdown spectroscopy (LIBS). Using KrF excimer laser, the characteristic spectral emission lines of C2 swan band at the wavelength of 516.5 nm and neutral copper at the wavelength range from 510 nm to 522 nm are acquired under ambient pressure in the ablation process of polyimide film and copper coated layer respectively. From a time delay from 50 ns to 4.05 μs from the beginning of the laser pulse, the temporal profiles of the spectral intensity are obtained in steps of 200 ns, which have a tendency of exponential decrease on both C2 and neutral copper. In particular, we concentrate our attention on the temporal intensity behavior of the Bremsstrahlung continuum emission that decides the proper set of detection time window, by which the monitoring sensitivity of LIBS is determined. Finally, using the information of the temporal analysis for each molecular, atomic, and continuum emission, the transition layer between polyimide and copper film is distinguished by their characteristic peak information.
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U2 - 10.1117/12.762025
DO - 10.1117/12.762025
M3 - Conference contribution
SN - 9780819470546
VL - 6879
BT - Photon Processing in Microelectronics and Photonics VII
ER -