Ultrashort Pulse Lasers. Rofin Baasel Benelux B.V. Hans Matser

Transcription

1 Ultrashort Pulse Lasers Rofin Baasel Benelux B.V. Hans Matser

2 Presentation Agenda Ultrashort Pulse Laser Basics When to use Ultrashort Pulse Lasers? Femtosecond or Picosecond? Which Wavelength is best for my Application? The Application Examples Solutions and Systems 2

3 Ultrashort pulse basics analogy Long Pulse Laser Lot of energy During a long time Low pressure More than one candle out 3

4 Ultrashort pulse basics analogy Ultrashort Pulse Laser Limited energy During an ultra short time Extreme high pressure Only one candle out Distance candles determine the required pulse length 4

5 Some Interesting Ultrashort Pulse Laser Facts Length of Pulse 10 ns 3 m 5 kw Speed of Light: km/s Pulse Width 10 ps 3 mm 5 MW Peak Power 100 fs 30 µm 500 MW 1 mm 2 mm 3 mm mm mm 5

6 Processing with ns Laser 10 Nanosecond Laser Processing Model Intensity 5 kw Laser Beam Time [ps] Recast & Debris Plasma & Drops Thermal Diffusion Mechanical Stress Heat Affected Zone Material 6

7 Processing with ps / fs Laser Ultrashort Pulse Laser Processing Model 500 MW x more peak power than ns pulse Intensity Time [ps] Plasma Material 7

8 Femtosecond (10 15 sec) or Picosecond (10 15 sec)? All depends on the Electronphonon relaxation time Defined as how long it takes to transfer the absorbed energy from the electrons to the lattice. Material EPRT Iron 0.5 ps 1 Aluminum 0.7 to 5.0 ps 1,2 Copper 50 ps 1 If the laser pulse duration is less than the relaxation time. Highest process efficiency Process is said to be Cold If the laser pulse duration is greater than the relaxation time. Larger heat diffusion depth Larger thermal damage to the bulk material [1]: Weikert, Oberflächenstrukturieren mit ultrakurzen Laserpulsen, Dissertation Stuttgart, Univ [2]: Ruf, Modellierung des Perkussionsbohrens von Metallen mit kurz und ultrakurzgepulsten Lasern, Dissertation, Stuttgart, Univ.,

9 Ultrashort Pulse Lasers Provide Superior Quality Cross section Polish of Stainless Steel parts Processed with different pulse widths 500 ns Pulse Width 10 ns Pulse Width 800 fs Pulse Width 9

10 Ultrashort Pulse Laser Applications Benefits Characteristics of Ultrashort Pulse Lasers: USP lasers have very high peak power USP laser pulse widths are in the range of time constants for coupling energy into lattice USP lasers provide multiphoton absorption The results are: USP lasers provide a thermal ablation no heat affect to remaining material USP lasers provide a higher level of precision (sub micrometer resolution) USP lasers improve quality (no melt layer, no cracking, no recast) USP lasers reduce or eliminate post processing ns Laser fs Laser 10

11 Ultrashort Pulse Lasers Provide Superior Quality Ablation in Hard Metal Ablated Area 100 ns Pulse Width [1] 10 ps Pulse Width [1] [1] Arnold Gillner, ILT Aachen 11

12 When to use Ultrashort Pulse Lasers? When you require high precision or high quality sub micron to 10s of micron range No burr, dross, recasted material When you have temperature senstive materials or brittle materials E.g. nitinol, polymers, glass When your parts are small or have small features When you need high selectivity of an ablation, e.g. multi layer processing When post processing shall be reduced or eliminated For cost reduction For yield improvement 12

13 Comparison ps and fs Pulses Example: Machining of Borosilicate Glass Ablated Area, 150 µm Depth 1064 nm, 10 ps 1030 nm, 800 fs Less cracks Wider process window, Higher process efficiency 13

14 Comparison ps and fs Pulses Example: Machining of Stainless Steel Ablated Area, 150 µm Depth 100 µm R a = 1 µm R a = 0.5 µm 1064 nm, 10 ps 1030 nm, 300 fs 14 Improved surface roughness Wider process window Less heat affected zone

15 Comparison ps and fs Pulses Example: Machining of PMMA Ablated Area, 150 µm Depth 100 µm 1064 nm, 10 ps nm, 300 fs Improved surface roughness Wider process window Less heat affected zone

16 Comparison ps and fs Pulses Example: Machining of Copper StarPico, 1064 nm, 2 µj: StarFemto FX, 1030 nm, 1 µj: 100 µm 1064 nm, 10 ps Wider process window Higher processing speed 1030 nm, 300 fs 16

17 How short is short enough? The application requirements define the best solution Higher Accuracy Better Process Quality Less Heat Affected Zone Higher Available Laser Power Higher single pulse ablation rates More Thermal Damage StarFemto FX StarPico PowerLine E PowerLine F Rofin has the full range of solutions 500 fs 10 ps 20 ns 120 ns Pulse Width 17

18 Wavelength What makes the difference? In polymers, glass and ceramics the photon E nm nm 515 nm energy of the IR light is too low for absorption. Initial absorption by Multiphoton Absorption Shorter wavelength provides: E 1 Higher energy of photons 10 Photons 7 Photons 4 Photons More efficient absorption Example: Required Energy for Fused Silica E2 E1 8 ev In polymers, glass and ceramics better quality and process efficiency often can be obtained with shorter wavelengths 18

19 StarFemto FX with SHG/THG 1030 nm 515 nm 515 nm 343 nm 1030 nm 343 nm Computer Controlled Switching between Wavelengths 19

20 Wavelength Flexibility Benefits Wavelength: 1552 nm Energy: 80 µj Cutting Speed: 0,5 mm/s Energy / mm: 2,4 J/mm Wavelength: 1030 nm Energy: 45 µj Cutting Speed: 1,5 mm/s Energy / mm: 0,12 J/mm Wavelength: 515 nm Energy: 15 µj Cutting Speed: 3,0 mm/s Energy / mm: 0,10 J/mm Advantage for 1030 nm / 515 nm Sharper edges Much wider process window 3 6 x improved speed > 20 x improved process efficiency [J/mm] Polymer Stent, Cut with StarFemto FX, 515 nm 20

21 StarFemto FX application areas Cutting of metal tubes (IR) SiO 2 /SiN ablation on crystalline solar cells (SHG) Cutting of metal sheets (IR) Drilling of metals (IR, SHG) Cutting of polymers (IR, SHG) Dicing of silicon (IR, SHG) Engraving of sapphire (SHG) Cutting of dielectrics (IR, SHG) Surface engraving of steel (IR) 21

22 StarPico Application Areas Surface engraving of copper alloys (IR), WC/Co, PCD SiO 2 /SiN ablation on crystalline solar cells (SHG, THG) Thin film ablation from glass (SHG) Thin film Ablation from Metal (IR, SHG): Paint, Polymers Cutting of battery foils (IR) Pre cutting of QFNs (IR, SHG) Drilling of Ceramics (IR, SHG) 22

23 Scanner Applications Example: Ablation of Sapphire, Structuring and Cutting Overlap % Pulse to Pulse Removal per scan: 0.5 to 10 s µm 23

24 Structuring Sapphire and Glass Application: Structuring Sapphire (Al 2 O 3 ) and Glass Application Examples: Watch Industry, Microfluidics, consumer products Rofin Solution: StarFemto FX, 1030 nm or 515 nm StarPico, 1064 nm or 532 nm Multipass scribing with scanner Ablation 10 W: in Sapphire: 3 mm³/min in Boro Silicate Glass: 4 mm³/min No chipping with StarFemto FX Structuring of Saphire, 50 µm depth per step Texturing of Glass Ablation of Tantalum from Glass 24

25 Scribing Glass Application: Scribe thin lines into glass Top View 45 µm 80 µm Rofin Solution: StarFemto FX, 1030 nm or 515 nm StarPico, 1064 nm or 532 nm Multipass scribing with scanner Very good edge quality, no chipping Effective scribe 15 W, Borosilikat Glass: mm/s for 50 µm 100 µm scribe depth Scribe Depth: 50 µm 100 µm 25

26 Scribe & Break Sapphire and Glass Application: Diced Boro Silicate Glass (manual breaking) Laser Scribe 50 µm Scribe & Break of Sapphire and Glass Application example: Consumer products, semiconductor, LEDs Rofin Solution: StarFemto FX, 1030 nm or 515 nm StarPico, 1064 nm or 532 nm Multipass scribing with scanner Very good edge quality Clean fracture face Fracture Face Laser Scribe 100 µm Fracture Face 700 µm 700 µm 26

27 Full Cut Saphire and Glass Application: Cutting Sapphire (Al 2 O 3 ) and Glass Application Example: Consumer Products Cut of Sapphire Rofin Solution / Advantages: StarFemto FX, 1030 nm or 515 nm StarPico, 1064 nm or 532 nm Multipass cutting with scanner Best quality, no chipping Cutting Speed for 350 µm thick display glass: 0.5 mm/s Cut of glass 0.17 mm thick 27

28 Structuring Metals Application: Structuring Stainless Steel, Copper and other metals Application Examples: Industrial Safety Discs, printing plates, high precesion molds Burst Disc, groove depth 100 µm, width 100 µm Rofin Solution: StarPico, StarFemto FX Rofin complete solutions with CNC, scanner, VLM SW Ablation Rate: Stainless Steel: 0.3 mm³/(min*w) 1 2 mm³/min 2.5 D Circular shaped groove in Stainless Steel for mold, depth 40 µm, width 100 µm 28

29 Examples of Trenches in Stainless Steel 29

30 Scribing of polymers Application: Ablation of polymers FEP, PE, PU, mold,. Scribing of 50µm FEP film on metal layer Rofin Solution / Advantages: StarFemto FX, 515 nm / StarPico, 532 nm Scanner processing Minimized heat affected zone through the use of SHG wavelength Back metalization removal on QFNs 30

31 Fixed Beam Applications Laser Beam Cutting Nozzle Moving Direction Workpiece Cutting Gas Used for cutting of metals and polymers Higher energy required due to reflection losses in the cut Rule of thumb for metals: Energy [µj] = 10% of the material thickness [µm] High overlap: > 99 % Pulse to Pulse Low taper angle due to self focusing and higher energy 31

32 Cutting Metals Application: Full body cutting of stainless steel, Nitinol, brass and other metals and alloys with thickness of up to 0.5 mm Application Examples: Medical Devices, Watch Components Rofin Solution: StarFemto FX 1030 nm or 515 nm Precision Cutting Head Rofin complete solutions StarCut Tube, MPS Femto Cutting speed: mm/s Taper free Cut Stent cutting Cutting of watch parts 32

33 Cutting of Polymers Application: Full body cutting of Polymers like bio absorbable polymers (PLGA, PLLA), PMMA, acrylic or polyurethane of up to 0.5mm thickness Application Example: Stents, Intraocular lens, Medical devices Rofin Solution / Advantages: StarFemto FX, 1030 nm or 515 nm Cutting head or multi pass scanner processing Rofin complete solutions StarCutTube, MPS Application Example Cutting of Bio Absorbable Stent OD: 3 mm, WT: / 0,02 Cutting of Intraocular Lenses (IOL) Cutting of CFPs PLGA Stent cutting Laser: StarFemto FX, 1030 nm Speed: mm/s, single pass 33

34 Drilling Metals Application: Precise, highest quality drilling of metals with controlled taper angle (zero, negative, positive) Application Example: Fuel injector spray holes, high precision spray nozzles, ink jet holes Rofin Solution / Advantages: StarFemto FX Rofin complete solution with advance beam delivery Speed for hole diameter 200 µm: 2 s / hole High Resolution 34

35 Presentation Agenda Ultrashort Pulse Laser Basics The Rofin Products StarFemto FX StarPico The Application Examples Solutions and Systems 35

36 Rofin Micro Focuses on Solutions Manual Welding Lasers Desktop Performance Select Integral Tool Open Laser Systems Laser Cutting Systems Modular Processing System MPS Universal Workstations Laser Perforation Systems Laser Scribing Systems 36

37 StarFemto FX Control Unit Laser Head Scanner Optics Interface Board IPC Power Supply Chiller Cutting Optics 37

38 Modular Processing System (MPS) Cutting of Sapphire X/Y Axes: Motors: linear drive Travel: 200 mm x 300 mm Max. acceleration: 1 g per axis Max. speed: 500 mm/s Positioning accuracy: ± 2 µm per 20 C Repeatability: ± 1 µm per 20 C Base plate: 400 x 300 mm² (W x D) 38 Cutting of micro-mechanical parts Thin film scribing

39 High Volume Production Workstation Fully automated workstation for solar application 39

40 Thank you for your attention