© Fraunhofer ILT
J. Gottmann, M. Hermans, J. Ortmann, www.lightfab.de N. Repiev, F. Riedel, I. Kelbassa, R. Poprawe RWTH Aachen Univ.
3D MICRO STRUCTURES IN GLASS BY ISLE WITH HIGH SPEED MICRO SCANNER
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3D MICRO STRUCTURES IN GLASS BY ISLE WITH HIGH SPEED MICRO SCANNER Motivation: Digital Photonic Production in Glass
ISLE-parts and Micro Scanner
Scalability
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Product complexity
Conventional Production
Lot size
Photonic
Production
Conventional Production
Innovative business models
Individualisation for free Individualisation for free Complexity for free
Innovative products
Cost Cost
Producer
Product
Providing-Value Value-Co-Creation
Producer Customer
Product
Environment
Photonic
Production
Digital Photonic Production – Vision
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Selective Laser-Induced Etching, “SLE”
fs laser radiation
v=1-10,000 mm/s
Wet etching
HF or KOH
Processing steps:
1) Selective modification of
the structure in the volume
by fs laser radiation
2) Selective wet chemical
etching of the modified
structure
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Experimental – Selective Etching
Etch rate of unmodified material r0 =0.21µm/h ± 0.015µm/h
Selectivity S: 𝑆 =𝑟𝑠+𝑟0
𝑟0 ; High Selectivity high aspect ratio
2 mm
l S~1400
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Motivation – What is Possible
By stacking single lines together SLE enables 3D-Microproduction of
Precise (blind) holes & grooves
Complex microfluidic devices
Already assembled micromechanics
in transparent materials like fused silica and sapphire
for applications like electrical vias, cell detection and sorting, filtering, drop making, fibre tip placement, injection nozzles etc.
Bellouard 2012 Matsuo 2008
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Digital Photonic Production with ISLE
3D-CAD Model
in Layers
Selective Modification
by Laser Radiation
Removal of Modified Material
by Wet Chemical Etching
ISLE: In-volume Selective Laser-induced Etching 1 mm
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Digital Photonic Production: CAD to CAM
CAD:
3D object in
common file type
Check for
closed volumes
Connection to
surface for etching
For CAM:
Definition of laser
tracks & layers
Automatic slicing
Check for artifacts
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Digital Photonic Production: CAM
CAM:
Alignment and process control with included microscope
Automatic control of translation stage, scanner and laser
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Digital Photonic Production: CAM & Process control
Automatic control of translation stage, scanner and laser
Alignment and process control with included microscope
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Digital Photonic Production: Resulting Microfluidics
3D microfluidic device after etching before separation
Transparency is increased when filled with water (immersion)
Diffraction at modified lines
before etching
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Digital Photonic Production: Resulting Microfluidics
3D microfluidic device after etching before separation
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Digital Photonic Production: 3D Mixer
3D microfluidics with glass-ball inside reaction chamber
2 mm
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DPP: Planetary drive with herringbone gearing
Planetary drive with herringbone gearing printed in fused silica
2 mm
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DPP: Laval Nozzle
Laval nozzle inset manufactured with SLE in fused silica
2 mm
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Micro Holes Cut in Fused Silica
Holes cut in 1 mm fused silica e.g. for
Optical Fiber placement
Filtering applications
Openings in casings
Inlets for gases or fluids
Electrical vias
Min. hole diameter ~ 30 µm
Max. hole diameter ~ 1 mm
Max. hole length ~ 2 mm
Max. hole taper ~ 20 µm
Precision ~ 2 µm
500 µm
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3D Microfluidic Device e.g. for Medical Diagnosis
3D micro channel in fused silica for characterization of living cells:
Buried flat channel
Tapered inlet
Connectors for flexible tubes
Prototypes and series from your CAD data
CAD data handling on request
Min. channel height ~30 µm
Min. channel width ~ 10 µm
Max. structure height ~ 2 mm
Max. structure width ~ 10 mm
1 mm
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3D Micro Mechanics e.g. for Micro Fluidics
3D micro mechanics in fused silica:
Free rotatable gear
Produced already mounted on axis
Available in buried micro channel
Prototypes and series from your CAD data
CAD data handling by us possible
Min. gap height ~20 µm
Min. gap width ~ 10 µm
Max. structure height ~ 2 mm
Max. structure width ~ 10 mm
1 mm
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Micro Scanner for Integration in Your System
Flexible Micro Scanner for your xyz stage system Designed for:
Research and application labs
1 µm focus radius (l~1µm), >0.2 m/s on 500 µm
Prototypes and small series of micro structures
Matched for Lasers with 0.1-5 MHz, 1-20 W
Properties
Scanning field 1 mm with lens f=10 mm
Reflected-light microscope included
CAM software, adapted to your system
Extendable with modules tailored for your needs
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High speed Micro Scanner for Volume Production
High speed micro scanner for high throughput:
1 µm focus radius (l~1µm), 10 m/s on 500 µm
Series of micro channels and holes
Matched for Lasers with 5-100 MHz, 20-150 W
Properties:
Scanning field 1 mm with lens f=10 mm
x-y stage and fast focusing included
Microscope & absorbed power meter included
CAM software
Tailored scanner for optimized throughput
500 µm
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Scope of Applications for Micro Scanners
Small focus (< 2 µm), high precision (< 1 µm) combined with large scanning velocity (0.1-10 m/s) are demanded in e.g.:
Micro structuring by ablation with high precision
Cutting of shaped holes
Crack free markings inside glasses
Fabrication of waveguides
Nanostructures (Ripples, Nanoplanes)
2 photon polymerization with high velocity
Structuring by ISLE
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OUTLINE
Motivation: Digital Photonic Production in Glass
ISLE-parts and Micro Scanner
Scalability by High Speed Micro Scanner
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ISLE with high average power laser (30 W) 8 mm long micro-channels in fused silica
Scanning velocity 10 m/s on 630 µm circles, Focus radius 1 µm, 0.5 & 5 ps
Repetition rate 27 MHz, Average power 10–30 W
Crack-free channels with 0.5 ps possible
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5 ps 24,3 W
0.5 ps 24,3 W
0.5 ps 16,2 W
630 µm
630 µm Scanning
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Drilling of Glass with High Speed Micro Scanner
Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:
Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz
Focus diameter: 2 µm
Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm
Track velocity: 3 m/s, Processing time per hole: 23 ms
Removal rate: 1.3 mm3/s resp. 0.17 mm3/Ws
27W 18W 8W 5.4W
400 µm
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Drilling of Glass with High Speed Micro Scanner
400 µm
Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:
Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz
Focus diameter: 2 µm
Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm
Track velocity: 3 m/s, Processing time per hole: 14 ms
Removal rate: 2.2 mm3/s resp. 0.28 mm3/Ws
34W 24W 8W 5.4W
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Drilling of Glass with High Speed Micro Scanner
400 µm
Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:
Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz
Focus diameter: 2 µm
Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm
Track velocity: 3 m/s, Processing time per hole: 9 ms
Removal rate: 3.5 mm3/s resp. 0.3 mm3/Ws
40W 30W 11.5W 5.4W
© Fraunhofer ILT
Drilling of Glass with High Speed Micro Scanner
400 µm
Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:
Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz
Focus diameter: 2 µm
Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm
Track velocity: 3 m/s, Processing time per hole: 6 ms
Removal rate: 5.2 mm3/s resp. 0.45 mm3/Ws
40W 30W 11.5W 5.4W
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Summary
ISLE is suitable for Digital Photonic Production
ISLE is Scalable
3D Microfluidics and Assembled Micro Mechanics
Flexible Micro Scanner for Prototypes from CAD
High Speed Micro Scanner for high Throughput of e.g. Holes and Micro Channels
Spin-off LightFab for: Micro Scanners and Production of ISLE-parts
Acknowledgement:
Funding: NRW.Transfer Science-to-Business Pre-Seed to prepare the spin-off
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Outlook
Our Tasks:
First time right
Float glasses
Process control
Process chains
Needs:
Description of modification processes
Control of stress, crack prevention
Basis for selectivity: Defects or thermal history?
Fast dynamic diagnosis
Control of focus: time & phase & aberrations (PFT)