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PICOSECOND LASERS:
Versatile, High Quality Micromaching
Dirk Müller, Ph.D.Bernhard Klimt
mueller@lumera-laser.com
www. LUMERA-LASER .com
PICOSECOND LASERS: Versatile, High Quality Micromachining
Our Parent Company
PICOSECOND LASERS: Versatile, High Quality Micromachining
LUMERA: Part of ATON Technology
Headquartered in Kaiserslautern, Germany
Corporate Overview
• Founded in 2000, LUMERA LASER has established itself as the leading picosecond laser manufacturer
• Since 2008 financially backed by the ATON Group
• Over 600 delivered Systems (>400 in 24/7 operation)
• We strive to provide our customers with: Best value in industry Knowledgable customer service
(before and after sales) Long term partnerships
The LUMERA LASER Team
PICOSECOND LASERS: Versatile, High Quality Micromachining
• Total Head Count ~ 100 Manufacturing 25 Engineering 9 R&D 8 Process Development 5 Customer Service and Sales 8 Supply Chain, Finance, Admin 13
• Key areas of expertise Optical and Laser Physics Ultrafast Pulse Generation Process Development (over 1000 samples) Mechanical Engineering Electrical Engineering
Ultrashort Pulsed Lasers
How short is ultrashort?
PICOSECOND LASERS: Versatile, High Quality Micromachining
Picoseconds
1 ps
1 ps 3 x thickness of hair
a picosecond is
to a second
what a day is
to the age of the
universe
or…
One millionth of one millionth of a second… 10-12
PICOSECOND LASERS: Versatile, High Quality Micromachining
Material Ablation
PICOSECOND LASERS: Versatile, High Quality Micromachining
Ehn = DEatom
Ehn < DEatom
absorption wavelength is material specific
absorption wavelength is material inspecific
linear absorption
works even at low intensities
nonlinear absorption
requires strong intensities
|g>
|e>
|g>
|e>
Linear vs. Nonlinear Absorption
Non-linear Ablation Threshold
PICOSECOND LASERS: Versatile, High Quality Micromachining
ablation threshold
Gaussian beam
heat deposition
ablation
region
Intensity > ablation threshold leads to ionization and material
removal
Intensity < ablation threshold contributes to heating
0.2 to 2.0 J/cm2
PICOSECOND LASERS: Versatile, High Quality Micromachining
hatch
~30% overlapping
Process Strategy
One disk at a time- Energy density 1J / cm²- 30 µm spot => 10 … 50 µJ- One-shot ablation: 50 nm – 1 µm
Move beam and repeat- Hatch multiple lines- High repetition rate (> 500kHz)- Max out scanner speed (> 10m/s)
PS laser machining advantages- no melt- no burrs- no microcracks
Advantages of Picosecond
• No heat affected zone (HAZ), gentle machining
• High spatial precision and quality
• Machining ANY material with one tool
psns
Cr-photomask (~4 µm)
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Nanosecond vs. Picosecond
Al
PVC
f 100µm,
1 mm thick
f 170µm, 0.3 mm thick
nano pico
PICOSECOND LASERS: Versatile, High Quality Micromachining
Total Cost of Ownership - 24/7 Operation
Initial Investment- 6W 100k€- 75W 200k€- 5 year amortization- 10% interest on capital
Operating cost- electricity 4k€/a- preventive service 4k€/a
Consumables- Diodes (20,000hr) 10k€/a- Chiller (15,000hr) 5k€/a- other 1k€/a
$5-$10/hr
Machining Sensitive Materials
Courtesy of VTT,
Laser Processing, FinlandPICOSECOND LASERS: Versatile, High Quality Micromachining
Complex Features in Metal
Bodhi Tree
25 µm Brass
24,000 Outlines
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
2.5 D Machining of any Material
glass
cost $3
removal of ~ 1,000 mm3
mammoth tusk
cost $1.50
WC
cost $6
3 cm
Ra~ 200 nm
From Drawing to Work Piece
1 mm
1 mm
CAD File
Machined Result
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Market Developments
Mechanical drilling- 20 holes/s per drill head- 6 drilling heads in machine (120holes/s)- Each bit lasts 2000 holes- Drill bit cost 200€/hr
CO2-lasers displaces mechanical drilling - lower cost- acceptable quality
ps-lasers start to replace CO2
- desired hole diameter shrinking below 100µm- ps-lasers penetrating market 70µm and below- up to 1000 micro vias/s with split beam
PICOSECOND LASERS: Versatile, High Quality Micromachining
One-sided Trepanning
top diameter 70µm
bottom diameter 50µm
thickness 0.1mm532nm, 400kHz, 10W30µm focus300 holes/sec
80.000 holes/$
top
bottom
side
PICOSECOND LASERS: Versatile, High Quality Micromachining
Two-sided Trepanning
top diameter 70µm
bottom diameter70µm
thickness 0.1mm532nm, 400kHz, 10W30µm focus300 holes/sec
80.000 holes/$
top
bottom
side
PICOSECOND LASERS: Versatile, High Quality Micromachining
Micro-vias by Percussion
blind hole dia. 50µm
Depth 50µm
Up to 1000 hole/s
PICOSECOND LASERS: Versatile, High Quality Micromachining
Holes in Ceramics
Diameter : 100 µm
Thickness: 1 mm
1 hole/s
Cost: 360 holes/$
10% of cost compared to
mechanical drilling
1064nm, 50W
LED Wafer Cutting
• narrow kerf
• thinner substrates
• more materials
(Sapphir, GaN, GaAs)
• 300mm/s cut speed
• more devices / wafer
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Grooves and Holes in Silicon
200µm
50µm
200µm thickness
150µm diameter
5 holes/s
1500 holes/$
50 µm
150 µm round holes in Silicon
PICOSECOND LASERS: Versatile, High Quality Micromachining
Drilling Holes in Stainless Steel
250µm
250µm
100µm
Ø=250µm
thickness: 300µm
5s / hole processing time
$0.014/hole
PICOSECOND LASERS: Versatile, High Quality Micromachining
Slots in Metal Foils
50 µm
200 µm40 µm
20 µm
15µm slots in 20µm silver 30µm slots in 100µm tungsten
Structuring of Sapphire
Courtesy of Ulrich Klug, LZH
PICOSECOND LASERS: Versatile, High Quality Micromachining
Sapphire Cutting
thickness 0.5mm, 1mm/s cutting; HYPER RAPID 50, 355nm
no microcracks
1mm
PICOSECOND LASERS: Versatile, High Quality Micromachining
Cutting Display Glass
• The reason is in your pocket
• Display glass is getting thinner for…• Leighter weight• Less material consumption• Higher flexibility – literally
• Cover glass hardened• More scratch resistant• Less likely to break
• Hardened Glass is difficult to cut
PICOSECOND LASERS: Versatile, High Quality Micromachining
Cutting (Button) Holes into Glass
PICOSECOND LASERS: Versatile, High Quality Micromachining
Glass wafer, 0.5mm thickness, 3mm hole diamter
50W, 1064nm
Removal rate > 1mm3/s
500µm
Cutting by Ablation: Scoring
PICOSECOND LASERS: Versatile, High Quality Micromachining
Pros• Very high cutting speed
Cons• Two step process• Assembled stacks can‘t be cut
scoring at 2m/s through the hardened layer
hardened layer
Cutting by Ablation: Full Cut
PICOSECOND LASERS: Versatile, High Quality Micromachining
chemically tempered region
Pros• Eliminates bending step• Allows for cutting stacks• Arbitrary cutting contour
Cons• Slow cutting process• Maximum thermal impact
200µmcutting through at 40mm/s through 200µm thick glass
Cutting by Ablation: Double Sided
PICOSECOND LASERS: Versatile, High Quality Micromachining
chemically tempered region
Pros• Eliminates bending step• Faster cutting speed (>2x)• Arbitrary contours• Smaller kerf• Less thermal impact
Cons• Optical access from both sides
focus on surfaces focus on middleCutting through at 100mm/sthrough 200µm thick glass
PICOSECOND LASERS: A NEW LEVEL OF MICROMACHINING
Gorilla XG, 700 µm, at 500 mm/sec
Glass Scribing Using New Filazone™
bevel „perforation“
• Filaments extend through glass
• After breaking glass has laser-ground (FiLaZone™) surface
• NO MICROCRACKS
• No surface mark or debris
• Excellent bend strength
• Curved cuts possible
single pass
Courtesy of Filaser Inc.
Top
Bottom
Cutting Laminated Glass Stacks
• Multiple assembled layers can be cut • Aligned cut creates flush edge• Offset cut creates stepped layers – opening interstitial layer
Pre-cleaving
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Drilling Glass Wafers with UV-Bursts
Entrance side: 26 µm diameter
Exit side: ~ 10 µm
6000 holes/$
PICOSECOND LASERS: Versatile, High Quality Micromachining
Drilling Holes into Glass Wafers
500 µm thick 30–10 µm diam.
Percussion 20 holes/second
Measured diam. Variation
< 3%
2.5 D – Machining of Silicon
Lens array for
IR detector in satellite
PICOSECOND LASERS: Versatile, High Quality Micromachining
Laser Drilling of Diesel Injectors
Injector
Spray holes:
Ø ~100 µm,
P >1000 bar
1mm thick SST
60 / 120µm hole diameter
532nm, 25W
500kHz
through in 5s, ready in 15s, $0.04/hole
Courtesy of ExOnePICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Cutting Fiber Glass Composite
1mm/s with SR
1.0mm thickness
355nm
10mm/s cutting speed
3.6m/$
PICOSECOND LASERS: Versatile, High Quality Micromachining
Laser Scribing for Photovoltaics
Picosecond lasers
are under evaluation
for P2 and P3
scribing.
Scribing speeds of
several m/s
Minimized damage
zone leads to higher
efficiency
Photovoltaic – Contact holes
~30ns, 355nm ~10ps, 532nm
Ablation of SiO2-or SiN-layer on Si
This application is currently under large scale
proliferation with manufacturers in Asia
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Marking Diamonds
355 nm
line width 5µm
dimension < 500µm
Secure Currency
16µm diameter holes
large enough to see throughtoo small to collect dust
PICOSECOND LASERS: Versatile, High Quality Micromachining
PICOSECOND LASERS: Versatile, High Quality Micromachining
Marking Glass Capillaries
RAPID
l=355 nm
5µm linewidth
400 characters/s
1064nm
5µm linewidth
355nm
100 characters/sec
36,000 characters/$
50µm
0 5 10 15 20 25 30 35 40 45
0
10
20
30
40
50
60
70
Stability
Roomtemperature
Te
mp
era
ture
[°
C]
Time [h]
Pow
er
[W]
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
5124 AS 2010-11-17
Picosecond Laser: 50W @ 532nm
PICOSECOND LASERS: Versatile, High Quality Micromachining
Power fluctuation <1%
532nm Beam Performance at 50W
PICOSECOND LASERS: Versatile, High Quality Micromachining
Mx < 1.1My < 1.1
Astigm. 1 %Asym. 0 %
PICOSECOND LASERS: Versatile, High Quality Micromachining
Points to Take Home
• Sub-mircon resolution
• Highest level of quality
• ANY material with one laser
• Removal rate:
up to 60mm³/min with 50W
• Total Cost of Ownership in 24/7 operation:
$0.10 - 0.25/min
sapphire
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