PracticalPractical ApplicationsApplications ofof LaserLaser TechnologyTechnology forfor SemiconductorSemiconductor ElectronicsElectronics MOPA Single Pass Nanosecond Applications for Semiconductor / Solar / MEMS & General Manufacturing

Mark Brodsky US Application Laboratory Manager Overview

● General Industrial Laser Overview ● Sources and variables ● MOPA vs Q-Switch ● Typical laser uses for Electronics ● Gaussian vs Single Pass Pulses ● Benefits of High kHz and Peak power ● Application Examples

Not to be distributed without prior consent of SPI Lasers Wide Spectrum-Rules of Thumb

1.064 is industrial starting place for smaller but powerful spots Cut wavelength in half at Triple the price and less power Less absorption depth comes at a price of thermal stability

Not to be distributed without prior consent of SPI Lasers Lasers in Electronics

● MicroMachining ● A range of infra red, visible and ultra violet laser sources give fast machining of a wide range of materials

● Via Drilling ● CO2 Laser drilling machine: Package, Printed circuit board, Ceramic device Material: Glass-epoxy, Epoxy, Green sheet) ● UV Laser drilling machine: Package, Printed circuit board, Flexible board material: Glass-epoxy, Epoxy, Polymide)

● Stencil Cutting ● CO2 Laser drilling machine: Package, Printed circuit board, Ceramic device Material: Glass-epoxy, Epoxy, Green sheet) ● UV Laser drilling machine: Package, Printed circuit board, Flexible board material: Glass-epoxy, Epoxy, Polymide)

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● Plastic ● Ceramic ● Through Plating ● Strip / Remark

Not to be distributed without prior consent of SPI Lasers Nanosecond Lasers

● Predominantly solid state 1micron sources

●Rod - Nd:YAG, YVO 4

●Disk – Yb+:YAG

●Fiber - Yb+

Not to be distributed without prior consent of SPI Lasers Pulsed MOPA Fiber Laser

Amplifier Chain (GTWave Technology) directly modulated LD

Seed Pre-Amp Post-Amp Laser

Advantages of MOPA architecture: Pulse parameters can be controlled independently at different stages

Extensive pulse energy and peak power parameter space

Not to be distributed without prior consent of SPI Lasers MOPA Laser Technical Description

Seed Optical Yb GTWave TM Yb GTWave TM Fibre Optic Output Pulses Pulses Pre-Amplifier Power-Amplifier Beam Delivery

Seed Pump Laser Diode Pump Laser Diodes

Seed Laser Driver Pump Laser Driver Pump Laser Driver

Main Control and Monitoring Electronics

User Control Electronics

• MOPA architecture • optical seed pulse generated by a single-mode semi-conductor (master-oscillator) laser diode • dual-stage Yb GTWaveTM fibre amplifier system pumped by multi-mode 9xx nm laser diodes • fibre-optic beam delivery cable terminated with collimator, and optional telescopes

Not to be distributed without prior consent of SPI Lasers SPI’s PulseTune Optical Pulses

Directly ModulatedNew Waveforms 20W @ 20W Q-Switched Fiber laser @ 20W

16.0 16 25 kHz 15 14.0 14 20 kHz 13 30 kHz 12.0 12 40 kHz 60 kHz 11 80 lHz 10.0 10 9 20 kHz 8.0 8 80 kHz

Power (kW) Power 7 6.0 6 peak powerpeak (kW) 5 4.0 4 3 2.0 2 80 kHz 1 0.0 0 -50 0 50 100 150 200 250 300 0 50 100 150 200 250 300 350 Time (s) time (ns) Increasing rep rate by using different Increased rep rate Wave Forms with shorter pulse significantly reduces peak lengths limits peak power reduction power

Not to be distributed without prior consent of SPI Lasers Marking Optics – Galvo Systems Mirror(2) Beam Aperture Expander Scan Head

Pupil Spacer iBDO Spacer F-Theta Lens Spot Size Marking Plane

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● Equals High Speed Processing

Not to be distributed without prior consent of SPI Lasers Spot Overlap: Marking quality up-close (one of several quality measures) Half the story!

No Spot Overlap Spot overlap is a key • visible mark • poor resolution ● Greater overlap produces a more continuous mark appearance • dotted-line ● >60% overlap desired for many marking applications

To increase spot overlap <5% Spot Overlap ● Slow down the mark until the • improved mark pulses overlap • low resolution • “scallop” edge Or (better put)

● Increase the pulse repetition rate at your desired marking speed ! >60% Spot Overlap • desired mark • high resolution • smooth line edge

Not to be distributed without prior consent of SPI Lasers Higher KHz provides smoother

●Spot overlaps only works when transition energy is has been passed.

●Less ablation, more material conversion

Not to be distributed without prior consent of SPI Lasers Solar Energy/Display Technology ● Scribing Transmissive Conducting Oxide (TCO) ● Typically Indium Tin Oxide (ITO) ● Careful control of the pulse energy is crucial to; ● completely remove the film, ● produce minimal burr to the patterned edge, ● lack of cracking/delamination of the TCO ● no damage to the glass substrate.

20W; 25kHz WF0 20W; 125kHz WF2 1m/s scan speed 1m/s scan speed 80m scribe width 40m scribe width

Not to be distributed without prior consent of SPI Lasers Different Beam Quality & Pulse Energy The right tool for every job!

Series SM RM/HS HM

M2 <1.3 <2 ~3.2

Power 10W / 20W 10W / 12W / 20W 30W / 40W Key attribute Fine feature Multi purpose Wider lines <25micron 35-80micron >60micron

Application Scribing (P1) General marking and Wide marks deep Fine marking micro-machining engrave area/logo

Not to be distributed without prior consent of SPI Lasers Comparison of M 2 on Application

● What is best for Snap and break in ceramic 20W SM 1.1 20W HS 1.8 40W HM 3.2

Pulse with smallest M 2 has highest power density but may not be best for the application!

Not to be distributed without prior consent of SPI Lasers Flexible Tool - Diverse Applications

Images and samples courtesy of: Miyachi Unitek, Electrox, LMCo & Orotig Silicon Processing

● Scribing and Cutting ● Low rep rate 25kHz ● Deep scribe ● High level of debris ● High rep rate >100kHz ● Shallow scribe ● Low level of debris ● Drilling ● Similar effect to above ● >400holes/s in 200µm Si wafers with 20W laser ● Diameter circa 50 µm ● Marking ● Can be smooth on surface ● But no circuitry can be below

Not to be distributed without prior consent of SPI Lasers Molybdenum thin film ablation

● P1 scribe ● Electrically conducting back contact film for CIGS or CIS modules ● 0.25-1 µm thick ● 125kHz, 4 m/s ● 30-40µm wide lines on 0.2 mm pitch

Not to be distributed without prior consent of SPI Lasers Enhanced Ohmic conduction ● Annealing of thin metallic film ● Array or overlapping spot fill techniques ● Enhanced contact with underlying layer ● Control of pulse to minimise damage

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Difficult to process TG ~3000°C ns Pulsed fiber laser 20W HS Good solution for micromachining

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Fired and Green Ceramic

Half mm Copper Heat

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● Cutting ● Drilling ● Mould cleaning ● Micro-machining

Not to be distributed without prior consent of SPI Lasers LaserLaser ProcessingProcessing ApplicationsApplications

The majority of laser materials processing applications are impacted by: Peak pulse power which is typically required to overcome processing thresholds. kW Pulse energy which governs the amount of thermal energy available to effect any material processing. mJ Pulse duration impacts beammaterial interaction time. ns Power Density – which reflects the intensity of the laser energy on the substrate. W/mm2 Average Power – typically governs productivity and processing speed W Pulse M 2 – Spike, Hammer, or “Hoss” Hat

It is often a combination of these parameters that needs to be considered in pulsed laser materials processing applications. Conclusions ● MOPA ns pulsed fiber lasers offer: ● Front end loaded pulse energy ● High peak power - High kHz processing for speed ● Expanding application space

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