From pico to femto: Laser technology for large area thin ... · Laser Welding/brazing Marking. ......
Transcript of From pico to femto: Laser technology for large area thin ... · Laser Welding/brazing Marking. ......
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From pico to femto:
Laser technology for large area thin film and micromachining
Precisiebeurs 2012
Laser technology for large area thin film and micromachining
• ECN and laser technology
Laser Welding
Marking
Cutting
Thin film processing
Micro machining
Laser technology for large area thin film and micromachining
• ECN and laser technology
Laser Welding/brazingMarking
Cutting
Thin film processing
Micro machining
Laser technology for large area thin film and micromachining
• ECN and laser technology
Laser Welding/soldering
Marking
Cutting
Thin film processingMicro machining
Thin film Solar
Source: Thin Film Solar CellsEd. J. Poortmans, V. ArkhipovFrank Lenzmann
2 μm
Thin film: structure
• Example: NIP Cell on nontransparent foil.
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Thin film: structure
• Example: NIP Cell on nontransparent foil.
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Thin film, Serialisation basic technologies
• Back end –
R2R
–
Sheet to sheet
• Laser –
Depth selective (wavelength, pulse energy, pulse width)
–
Alignment
• Inkjet –
Conductive (Ag,Cu, Al)
–
Insulator
Serialisation: a generic process for thin film
• In process interconnection
• P1,P2,P3 –
Alignment on large substrates
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Transparent substrates
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No R2R possible
–
8 steps
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Deposition and structuring combined
• Back end interconnection
• 7 process steps (4 deposition, 1 laser, 2 inkjet)–
Deposition of all layers
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Selective ablation
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One setup / one machine
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Transport and alignment reduction
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R2R compatible
Serialisation: a generic process for thin film
Σ
4 steps
Example P2 scribe
Example P1 scribe
Processing thin film Si
ITO removal
Amorf NIP Si on steel
λ
1030 nm
tp
1ps
Spotsize 30 μm
Processing thin film Si
Amorf Si, nip stack,10 x 10 cm samples, ECN Baseline
9 ps vs. 0.25 ps.
same optics, power, wavelength, sample, machine, software
2 different processes: layer fragmenting , layer ablation
Optimum.
below 1 ps
Processing thin film Si, pulse width
aSi, nip stack,10 x 10 cm samples, ECN Baseline
P = 1.9 W, Q = 100 kHz, fΘ
160 mm, z = 0 mm, v = 2000 mm/s, ep
19 μJ0.25 ps, scribe width 40 μm 9 ps
100 μm 100 μm
Processing thin film Si
aSi, nip stack,10 x 10 cm samples, ECN Baseline
P = 0.5 W, Q = 100 kHz, fΘ
160 mm, z= 0 mm, v=1000 mm/s, ep
5 μJ0.25 ps
9 ps
100 μm50 μm
Processing thin film Si
aSi, nip stack,10 x 10 cm samples, ECN Baseline
P = 0.2 W, Q = 100 kHz, fΘ
160 mm, z = 0 mm, v = 100
mm/s, ep
2 μJ0.25 ps
9 ps
Processing thin film Si
100 μm 100 μm
Si solar cell structure
Processing Si
http://www.solliance.eu/
Si cell structure
Inkjet in laser pattern
200 μm.
Processing Si
http://www.solliance.eu/
Micro machiningPulse width 250 fs - 10 ps
Ripple structures, laser-induced periodical surface structure (LIPSS)
first discovery by Birnbaum 1965.
Ripples on steel I/IV
Ripples on steel II/IV
Ripples on steel III/IV
λ
1030 nm
tp 250 fs
Spotsize 30 μm
Ripples on steel IV/IV
Period 0.9 μmAmplitude ~ 200 nm
Laser technology for large area thin film and micromachining
• ECN and laser technology
Laser Welding/soldering
Marking
Cutting
Thin film processing
Micro machining
Al foil cutting I/IV
λ
1030 nm
tp 250 fs
Spotsize 30 μm
Samples not cleaned
Al foil cutting II/IV
Al foil cutting III/IV
Top view
Bottom view
Al foil cutting IV/IV
Side view
Cu foil cutting I/II
250 fs
10 ns
Cu foil cutting II/II250 fs
Micro machining SiN I/III
Volume subtraction on curved sample to create flat surface
mathematica
Dxf files
Micro machining SiN II/III
Micro machining SiN III/III
Micro machining, next step
Confocal measured feedback and calibration of shapes
Dxf files Product
30 x 30 cm area structuring
Tec 7 glass
See ECN standHardened glass
Engineering of an experimental system
All samples made by Adem femto – pico laser facility
ECN, Eindhoven HTC 29
http://www.adem-innovationlab.nl/home/
University of Twente, University of Delft University of Eindhoven+ ECN.
Phd students and capital investments.
Femto,pico or nano ?
High intensity, low average femto second very effective (all materials absorp),
Shorter pulse lengths give higher conversion efficiency (green and UV).
Each pulse result in a higher temperature, also femto.
Processing strategy remains necessary.
Wavelength vs. intensity absorption.
High thermal conductivity materials , accept longer pulses, higher pulse freq.
Low thermal conductivity materials, short pulses, longer time between pulses
Engineering of an experimental system
• System setup–
Open platform for laser experiments
• Mechanics–
2.5 m/s on one axis
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Integration of laser scanners with xy movement
–
R2R capability
• Optics–
Short pulse and high intensities
• Software–
Automation of experiments
• Process capabilities–
Tunable Pulse width
–
Three wavelengths available
Project AdemPlatform with focus on
Pulse width range , three wavelength solution.Pico second / femto secondRoll to roll and sheet to sheet. TCP/IP communication (camera, power, scanners, users)
One beam path approach compactallignment optics
Experimental system
Specs. adem system
Wavelength 1030 nm & 515 nm & 343 nm,
pulse width 250 fs – 10 ps
10 W @ 1030 nm, 5 W @ 515 nm, 2 W @ 343 nm (Light conversion)
XYZ (1300 mm x 600 mm x 200 mm) accuracy. X 5μm , Y 5μm, Z 3μm high speed Y axis, 2.5 m/sR2R handling (300 mm, ~ 0.5 m/s)
Downflow (prevent optical damage)(NXP)
Laser safety cabinet, optics interfaces(ECN)
Laser (Lightwave)
Optical table(Philips)
Optics(Sill/molenaar)
Translation system(Q’sys)
Experimental system
Software and communication
Rocks (master)
Excelsheet
Samlight(scanners)
Rocks (slave)
XY2-100TCP/IP RS232 trigger
Aerotech
Fire wire
Software and communication
Step and scan
Software and communication
Smart vision in combination with Rocks
Rocks have the ability to interact on position
information from a machine vision camera.
Rocks support smart vision cameras:
•
Philips Inca and Dica series
• National Instruments 177x series
• Cognex Insight Micro series
Software and communication
Camera integration
R2R
Simple foil handling
Integrated in movement system
Non indexed, relative position
R2R , non indexed
R2R, non indexed