laser microdrilling in industrial · pdf fileoctober 04 industrial business review 1.market...

October 04 Industrial Business Review

"Laser Microdrilling

in Industrial Applications"

Dr. Dimitris Karnakis

Oxford Lasers Ltd., Didcot OX11 7HP (UK)


1. Market Overview

2. Which Lasers to use?

3. Physical Mechanisms

4. Laser Drilling Techniques

5. Case Study: Fuel-Injectors

6. Future Trends

OutlineOutline


MicroDrillingMicroDrilling Industrial Applications Industrial Applications

Industry Sectors

-Semiconductor

-Automotive

-Aerospace

-Electro-optics

-Photonics

-Medical

-Food

Manufacturing Applications

• Inkjet Printer Nozzles

• Via Circuit Electrical Interconnects

• Optical Switch Fab

• Test Probe Cards

• Gas Flow – Chemical Sensors

• Leak Detection

• Biomedical Sensors

• Fuel Injection Nozzles

• Aerosol Atomisers

• Engine Silencing

• Food Packaging

• Particulate Filters

• Solar Cell Technology

• Turbine Blade Cooling


Example ApplicationsExample Applications

PCB via drilling

Cardiac stent manufacturing

Inkjet printer manufacturing

Fuel-injection nozzle drilling 150µm Ø, 511nm, 1mm thick steel

valve

Injection hole

Fuel feed


Industrial Lasers Market (2004)Industrial Lasers Market (2004)

Global Laser Material Processing Market: ~$1.3 bn (2004)Annual Market Growth: 10% (10 yr average)Projected Worldwide Laser Market (2008) : ~$3 bn

Worldwide Laser System Installations

Europe

33%

N.America

31%

Japan

24%

Asia

9%

RoW

3%

Industrial Laser Sales (2003)

Solid-state

46%

CO2

29%

Other

5%Excimer

20%

Industrial Laser Applications

Market Segmentation (2003)

Medical

19%

Research

7%

Other

7%Material Processing

67%

Laser-Material Processing

Drilling

4%Marking

30%

Welding

13%

Microprocessing

13%

Other

8% Cutting

32%

Source: Laser Focus World,

BCC Inc. Market Analysis, Industrial Laser Solutions


Which Industrial Materials to Drill?Which Industrial Materials to Drill?

Metals Silicon

Plastics Ceramics

CVD Diamond


Examples of Laser Drilled ShapesExamples of Laser Drilled Shapes

rectangleshaped

angled

blind


Why Use Lasers to Drill Holes?Why Use Lasers to Drill Holes?

•Non-contact enabling technique

•High Processing Speed

•High Resolution

•Flexibility (hole size, shape)

•Compactness (small machine footprint)

•Cost effectiveness


Important Laser-Drilling MarketsImportant Laser-Drilling Markets

Dec 1996

Laser

43%

plasma

3%

photovia

42%

punch

3%

mech.drill

9%

Aug 2000

Laser

93%

other

2%

photovia

5%

Source: ESI

Main Drivers: Semiconductor (micro via-holes, ink-jet printing)

Aerospace (turbine cooling)

Emerging Markets: Automotive, Pharmaceutical, Biomedical

Source:Excellon Inc

Technologies to Make “Vias”

Via Size

Asp

ect

Rat

io (

dep

th/d

iam

eter

)

10:1

1:1

0.1:1

Thro

ugh

Via

sB

lind

Via

s

UV LaserCO2 Laser

Mechanical

0 50 100 150 200 250 300 (micron)


Micro-Via DrillingMicro-Via Drilling

Technology Comparison

Mechanical Drilling (hole Ø > 0.1mm)

Drill speed: ~ 500 holes /min

Cost ~$2400 / 105 holes

Laser Drilling (hole Ø < 0.025 mm)

Drill speed: ~ 34000 holes /min

Cost <$1 / 105 holes

Blind via holes

Substrate CoreDielectric

Copper

Dielectric

Copper

Metal Core Multilayer PCB

Copper

Copper

Invar

Blind via holes


Copper

Dielectric

Copper

Metal Core Multilayer PCB

Copper

Copper

Invar


Copper

Dielectric

Copper

Copper Clad Laminate Metal Core Multilayer PCB

4 layer PCB

Copper

Copper

Invar

Consumer ElectronicsExample: Hand-held devices

(Mobile phones, video & digital cameras)

Real-Estate Requirement:

High Packing Density of PCB Boards

!Multi-layered PCBs needed

! Via interconnects holes needed


Indicative Cost of Laser ProcessingIndicative Cost of Laser Processing

Capital Cost

• Laser/Optics

• Motion (CNC, galvo, etc)

• Cleanroom/ Environment

• Machine Vision

• Software

• Sample Handling

• Metrology Equipment

• Safety Equipment

• Downtime

Main Q: Which laser to use?

Running Cost

• Optics

• Laser consumables

odiode arrays

oflashlamps

oassist gases

• Water, Power

• Sample postprocessing

• Other consumables


1. Market Overview





6. Future Trends


Why Use Why Use PulsedPulsed Lasers to Drill Holes? Lasers to Drill Holes?

Pulsed Lasers :

•Provide Overall Excellent Feature Quality

Short interaction time with materialSmall heat affected zone (HAZ)

•Fine Resolution

Controlled material removal

•Enable Machining of Transparent Materials

High laser intensity enables micromachining of any material


Which Laser to Use?

From P.R. Herman et al.rApplied Surface Science 154–155 (2000) 577–586

Feature Quality Proc.Speed

Industrial Laser Choice

•CO2

•Excimer

•Copper

•DPSS

•Ultrafast (ps, fs)

•Fiber/Disc

It is always a case of balancing

by adjusting laser parameters

wavelength, pulse width, power, rep.rate,etc


Available Industrial LasersAvailable Industrial Lasers

Courtesy: Corelase

CVL

CO2


NdNd:YAG Laser Drilling:YAG Laser Drilling

Typical Laser Specs:

Wavelength: 1064, 532, 355, 266, 213 nm

Power: 1 – 103 W

Pulse Length: 10-12 – 10-3 s

Rep.Rate: 1 Hz – MHz

Focussability: M2 ~ 1 - 40

Price: from $20k +Aerospace Turbine blade cooling

SemiconductorSilicon wafer drilling


Copper-Vapour Laser DrillingCopper-Vapour Laser Drilling

1 mm steel

50 µm s. steel 1 µm gold

Reservoir 100 µm x 1000 µm

Capillary 15 µm x 600 µm

Reservoir 100 µm x 1000 µm

Capillary 15 µm x 600 µm

Wavelength: 511&578 nm

Power: up to 75W

Rep.Rate: 5-30 kHz

Pulse Length: 25 ns

Focusability M2=1.5

Price: from $60k+


ExcimerExcimer Laser Drilling Laser Drilling

Typical Manuf. Applications

• Inkjet printer nozzles

• Biomedical sensors

• Environmental sensors

• Telecom

• Display

HOMOGENISERS

BEAM

SHAPING

FIELD

LENS

CONDENSOR

LENS

MASK

PROJECTION

LENS

SAMPLE

©Exitech Ltd


UltrashortUltrashort-Pulsed Laser Drilling-Pulsed Laser Drilling

Picosecond or Femtosecond Lasers

Ti:Sapphire, mode locked Vanadate

Wavelength: 780 or 1064 nm and harmonics

Power range: up to10W, up to 500kHz

Pulse Length: 10ps – 30fs

Advantages•Material independent•Min HAZ•No post-processing necessary

Disadvantages•High Cost ($150k+)•Complex•Frequent Maintenance•Not mature yet


Dual-Laser Beam DrillingDual-Laser Beam Drilling

© M.Kauf, Excellon Corp


Q: Q: ““Which laser to use?Which laser to use?””

Answer:

Every application is different and should be judged on its merits


1. Market Overview





6. Future Trends


Basic Laser-Hole Drilling Basic Laser-Hole Drilling SetupSetup

X-Y Table

Laser

Beam Shaping Optics

Target

Waveplate

Gas-Assist

Nozzle

Objective

Lens

Turning

mirror

Optics

Adjust

Stage


Laser-Hole Drilling: Basic DefinitionsLaser-Hole Drilling: Basic Definitions

)d(Diameter

)t(ThicknessRatio_Aspect =

t

Laser Spot Size

2w0 = (4f !f M2 / " D)

Laser Intensity

I(x)=(2P/"w02) exp(-2r2/w0

2)

Hole Taper Angle

# = tan-1(d1-d2 / 2 t)

Focussing Lens

Fourier Transformer


Laser-Drilling: Important ParametersLaser-Drilling: Important Parameters

Type

Wavelength

Output Power

Pulse Energy

Rep.Rate

Pulse Length

Beam Diameter

Beam Polarisation

Beam Divergence

Spatial

Temporal

Beam Intensity Profile

Laser

Absorptivity

Reflectivity

Refractive Index

Surface Roughness

OPTICAL

Thermal Conductivity

Specific Heat

Melting Point

Boiling Point

Evaporation Enthalpy

Surface Tension

Vapour Pressure

THERMOPHYSICAL

Density

Hardness

Poisson Ratio

Young's Modulus

MECHANICAL

Material

Lens NA

Spot Size

Shot Overlap

Gas Assist

Focal Plane

Processing Speed

Drilling Technique

Processing

! IMPORTANT NOTE:

Most parameters are interrelated and vary with temperature, pressure, time,etc.


Example: Importance of Pulse LengthExample: Importance of Pulse Length

© Lambda-Physik

Pulse Length

(FWHM)

Pea

k P

ow

er (

kW

)

Laser Ablation

by Melt Expulsion

Laser Ablation

by Evaporation

Resolution (µm)

Low Resolution,

>100 µm

1

10

102

High Resolution,

<10 µm


1. Market Overview





6. Future Trends


Laser Drilling TechniquesLaser Drilling Techniques

Direct Focussing-Coherent Sources ! tight focussing-Focussed Spot Size ! hole size-High Fluence ! high drilling speed-Low Pulse-to-Pulse Stability

Projection Imaging-Incoherent Sources-Mask Projection ! shape flexibility-Low Fluence ! slow drilling

Laser

Focal Plane

Image Plane

Laser

Percussion Drilling = Static Drilling


Laser Drilling TechniquesLaser Drilling Techniques

For Fast Drilling

! Sample or Beam Motion Necessary

! Need High Fluence = Small Spot Size

! Crater < Hole Dimensions

! Helical motion for High Aspect Ratio Features

(Technique offers Good Repeatability, Versatility)

Laser

Beam Path

Helical

Motion

Trepanning Drilling


1. Market Overview





6. Future Trends


Fuel-Injection Nozzle DrillingFuel-Injection Nozzle Drilling

Main Technology Drivers

• Emissions Legislation

• Lower manufacturing cost

• Consumer demand for higher performance

Current Manuf.Technology: -wire EDM (min hole Ø: 130µm)-punching-mechanical drilling

Future Technology: Laser Drilling


Global Emissions LegislationGlobal Emissions Legislation

“…vehicle emissions are set to reduce in

all regions but with different criteria…”Courtesy: Ricardo Automotive consultancy


Diesel-Injection Nozzle DrillingDiesel-Injection Nozzle Drilling

Injector Hole Specification

• High Resolution

• High Aspect Ratio

• Best Accuracy

• Best Quality

• Backwall Protection

• Design Flexibility

• Production Cost

• Reliability

• Repeatability

• New Materials to drill

EU & US Emissions Standards Regulations

(2007) increasingly require: ! improved fuel combustion ! decreased hydrocarbon & particle emission

Automotive Industry needs: ! small spray droplets in piston chamber ! smaller diameter fuel-injector holes needed ! new drilling technology required

Micro hole Laser drilling


Diesel-Injection Nozzle DrillingDiesel-Injection Nozzle Drilling

Different Nozzles Geometries

Nozzle Internal View

No back wall Damage from Laser

High Speed Imaging


Diesel Fuel Filter DrillingDiesel Fuel Filter Drilling

• Fuel filters are used to block fuel impurities before they reach the injectors

Laser Drilling Speed: 100-500 holes / sec

Hole Diameters: 0.05 – 0.3 mm

Material Thickness: <1mm

Courtesy: Lasag Industrial Lasers

Laser-drilled section


Diesel-Injectors: Trepanning DrillingDiesel-Injectors: Trepanning Drilling

Steel

1mm thick


Gasoline-Injection Nozzle DrillingGasoline-Injection Nozzle Drilling

Different Gasoline InjectorConfigurations



•Four-hole nozzle

•250 µm diameter holes

•250 µm thick steel

•70 Degree angle

•5 seconds per hole



•Eighteen-hole nozzle

•500 µm diameter

holes

•500 µm thick steel

•60 degree angle

•45 seconds per hole


Laser Hole Drilling: Future TrendsLaser Hole Drilling: Future Trends

• Better Resolution(shorter wavelength, 4th, 5th harm DPSS)

• Higher Processing Speed(higher rep.rate, higher average power)

• Better Quality(shorter pulsewidth, higher motion control speed)

• New Complex Materials(alloys, composites, multi-wavelength systems)

• Industrial Robustness(compact, fully diode-pumped laser systems)

laser microdrilling in industrial · pdf fileoctober 04 industrial business review 1.market...

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