MEETING CHALLENGES WITH HIGH POWER UV LED SOLUTIONS · Online Session: Meeting Challenges with High Power UV LED Solutions TOTAL REVENUE in 2019 22.4 bn € GLOBAL BUSINESS UNITS

MEETING CHALLENGES WITH HIGH POWER UV LED SOLUTIONSOnline Session by Heraeus Noblelight

AGENDA

Introduction to Heraeus and Heraeus NoblelightUnderstanding irradiance and energy for optimizing UV curing processesImportant elements of a high power UV LED systemBenefits of high power UV LEDs: explore customer cases Q&A session

Online Session: Meeting Challenges with High Power UV LED Solutions7/21/20202

AGENDA



HERAEUS – A GLOBALLY SUCCESSFUL PORTFOLIO COMPANY

Online Session: Meeting Challenges with High Power UV LED Solutions

TOTAL REVENUE in 2019

22.4 bn €

GLOBAL BUSINESS UNITSmarket-oriented11

R&D EXPENDITURES7%

FAMILY-OWNED COMPANIES in GermanyTOP 10

More than 100 SITES

in 40 COUNTRIES

APPROX.

14,900 Germany 37%Rest of Europe 15%Asia 29%America 18%Africa/Australia 1%

EMPLOYEES WORLDWIDE

America25%

Asia42%

Germany11%

Africa/Australia

2%

Rest of Europe

20%

including staff leasing

Based on revenues excl. Precious Metals

7/21/20204

AGENDA



FACTORS THAT INFLUENCE THE UV PROCESS


› Spectral distribution› Irradiance and energy› Energy distribution› IR-radiation

UV lamp system

› Chemical components› Spectral absorption› Spectral reaction› Optical thickness

Formulation

› Dispensing method› Layer thickness› Process speed› Substrate

Product

7/21/20206

KEY FEATURES OF A UV LAMP SYSTEM


Irradiance, W/cm2

Profile of radiant power arriving at a surface, in a specific waveband Usually peak irradiance is reportedVaries with lamp output power, optics and distance from lamp to surface

Energy, J/cm2

Total energy arriving at a surface in a given timeTime integral of the irradiance profileInverse of speed

Spectral outputRelative radiant output versus wavelength (nm)UV LED lamps : narrow band wavelength distribution

7/21/20207

The physical properties of UV cured materials are affected by the UV lamp systems used in the process and the exposure conditions for the polymerization process

Reduction of UV as it travels through a coating follows a definite law

› Lambert-Beer Law A = log(I0/It) = Ɛcd› A = absorbance› Ɛ = molar absorption coefficient› d = path length

› Intensity of UV diminishes with depth and absorptivity of the coating

› Every coating / ink has its own characteristic absorbance› Top and bottom of a coating are subjected to different curing conditions

› Also influenced by photoinitiator concentration

› Balance polymerization at surface with polymerization at the bottom

ABSORBANCE OF LIGHT THROUGH A COATING


Top 1%

Bottom 1%

d

Light energy absorbed in top & bottom of any film thickness vs Absorbance

7/21/20208

What

› Optimization of UV exposure conditions based on the requirements of the UV cured material› Quantify key exposure conditions› Transfer the process to production› Set operating limits : Process Window› Monitor UV process

How

› Identify key physical properties of the final cured material› Vary key UV lamp exposure conditions independently› Measure effect on individual key physical properties› Properties can fail at different points› Determine minimum exposure & irradiance needed to meet all requirements

PROCESS DESIGN


https://uvebtech.com/images/091115/uv-qa1.jpg

0123456

20 30 40 50 60 70 80

cure

ass

essm

ent

Speed m/min

Low irradianceEvaluation of cure properties24μ clear coating, 385nm UV LED

8.7W/cm² scuff 8.7W/cm² adhesion


PROCESS WINDOW – VARYING IRRADIANCE


› High irradiance maximum cure speed› scuff = 50m/min› adhesion = 55m/min

› Low irradiance maximum cure speed› scuff = 50m/min› adhesion = 35m/min

› Changes in properties at lower irradiance / greater distance could be important in 3D curing applications

0123456

20 30 40 50 60 70 80

cure

ass

essm

ent

speed m/min

High irradiance Evaluation of cure properties24μ clear coating, 385nm UV LED


Cure assessment score: 5 = excellent 1 = very poor

7/21/202010

CLEAR COATINGS


› Cure speed independent of irradiance – above 1.3W/cm2

› Irradiance increases 5x› Small increase in cure speed

› 55m/min to 60m/min

0

5

10

15

20

25

30

2,8 3,9 6,8 8,7

cure

spe

ed m

/min

Irradiance W/cm²

Coating Bcure speed at increasing irradiance

12μ clear coating, 385nm UV LED

0

10

20

30

40

50

60

70

1,3 2,8 6,8 8,7

cure

spe

ed m

/min

Irradiance W/cm²

Coating Acure speed with increasing irradiance

12μ overprint varnish, 385nm UV LED

› Cure speed strongly dependent on irradiance› Irradiance increases 3x› Cure speed increases 25x

› 1m/min to 25m/min

7/21/202011

› UV LED 385nm

› 1 print layer black offset ink› Increase irradiance & record the minimum energy

needed to pass surface scuff and tape adhesion test› Higher energy = slower speed

› Increasing irradiance up to 2.0W/cm2

› No significant change in energy needed to pass either test› Increasing irradiance from 2.0 to 2.4W/cm2

› Significant decrease in energy (40%) needed to pass both tests

› Increasing irradiance from 2.4 to 8.7W/cm2

› Slight decrease in energy needed to pass both tests

› Suggests minimum threshold irradiance to cure the black ink to pass both scuff and tape adhesion tests

BLACK OFFSET INK – EFFECT OF IRRADIANCE


0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

1 1,4 2 2,4 2,8 3,7 6,8 8,7

Ener

gy U

VA2

mJ/

cm²

Peak irradiance UVA2 W/cm²

Minimum energy to cure vs Peak IrradianceBlack offset ink

Scuff Tape Adhesion

7/21/202012

› Printing wet-on-wet layers to increase film thickness and optical density of the ink layer

› UV LED 385nm

› Irradiance increases from low to high by x 3.6

› For 1x print layer energy to pass adhesion test› 2.4W/cm2 needs 0.166mJ/cm2

› 8.7W/cm2 needs 0.154mJ/cm2

› similar energy for low and high irradiance

› For 4x print layer energy to pass adhesion test› 2.4W/cm2 needs 0.331mJ/cm2

› 8.7W/cm2 needs only 0.184mJ/cm2

› just over 1/2 of the energy needed when using high irradiance

BLACK OFFSET INK – INCREASING PRINT LAYERS


0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

1 2 3 4

UVA

2 en

ergy

mJ/

cm²

Print layers

Minimum energy to pass adhesion test with increasing print layers

8.7 W/cm² 2.4 W/cm²

7/21/202013

Understanding irradiance and energy

› Physical properties of a UV cured material are primarily decided by the selection of oligomer & monomers

› Achieving required properties influenced by optimizing the UV exposure conditions› Irradiance› Energy / exposure time› Wavelength

› Determining the process parameters / process window is important› Design the UV lamp installation› Monitor the process

› Different UV curable formulations can respond differently to energy and irradiance and can be influenced by› Formulation / photoinitiator level› Absorbance › Optical density / film thickness

SUMMARY


AGENDA



DIFFERENT SOLUTIONS FOR DIFFERENT APPLICATIONS


Medium Power Class

High End Class

High Power Class

UV5000 Series

UV7000 Series

UV4000 Series

60+

40-60

20-40Pinning Class

UV2000 Series<20

The different products are clustered by the UV energy output per cm.Even numbers are air-cooled, odd numbers are water-cooled

Irradiance values & Power class


Semray® UV2000 Semray® UV4103 Semray® UV5000 Semray® UV5000M Semray® UV5000+ Semray® UV7000[no optics] [primary optics] [no optics] [primary optics] [primary + secondary optics] [no optics]

365 nm

385 nm

395 nm

405 nm

3.3 W/cm²2.3 W/cm

13 W/cm²20 W/cm

15 W/cm²35 W/cm

19 W/cm²40 W/cm

22 W/cm²55 W/cm

4.5 W/cm²3.3 W/cm

15 W/cm²23 W/cm

18 W/cm²40 W/cm

23 W/cm²45 W/cm

15 W/cm² @ 50 mm30 W/cm

26 W/cm²65 W/cm

5.5 W/cm²4.2 W/cm

18 W/cm²28 W/cm

23 W/cm²42 W/cm

30 W/cm²47 W/cm

30 W/cm²70 W/cm

5.0 W/cm²3.5 W/cm

17 W/cm²26 W/cm

20 W/cm²40 W/cm

26 W/cm²41 W/cm

26 W/cm²65 W/cm

Data based either on lab measurement or simulation

DIFFERENT APPLICATIONS, DIFFERENT SOLUTIONS

Irradiance values & Power class

7/21/202017

WHAT IS A WATER COOLED SYSTEM?

Electrical cabinetChiller

UV LED lamp

A system includes a UV LED lamp, an electrical cabinet (MCU/PSU/Control panel), a chiller + necessary cables & hoses

The chiller and electrical cabinet sizes are chose according to the lamp size



KEY 1: THERMAL MANAGEMENT

Wire BonderGold bondig wires fromHeraeus Electronics

Pick & PlaceThermoconductivity &Highest Density Package

Pattern PrintSoldering paste fromHeraeus Electronics

7/21/202019


Micro OpticsUVA resistant & transparent micro optics

Module DesignThermal conductor &Heat sink

Soldering OvenVacuum & Heating

CablingPerformance & NTC

Thermal Imaging SimulationPerformance & NTC


7/21/202020



PerformanceIntensity at working distance &Radiation homogeneity

Infrared ImagingThermography of individualmodules & complete unit

7/21/202021

Bare bone chip

Heat sink

Emission window

Substrate

No Optics [Semray UV5000 / Semray UV7000]

Primary Micro Optics [Semray UV5000M]

Primary and Secondary Objects [Semray UV5000+]


KEY 2: PHOTON MANAGEMENT

Contacts

Primary micro optics

Secondary optics

120°

60°

7/21/202022



LAMP WIDTH (mm)

7/21/202023

Irradiance at different working distances (a simulated comparison at 385 nm)

No Optics[Semray UV5000, 385 nm]

Primary Micro Optics[Semray UV5000M, 385 nm]

Printing [web offset & digital], Coating, Converting, Optical film, Electronics

0 20 40 60 80 1000

5

10

15

20

25

30

35

Pea

k in

tens

ity [W

/cm

²]

Distance z [mm]

no optics primary optics secondary optics

Optics Concept[Semray UV5000, UV5000M, UV5000+, 395 nm]

Primary And Secondary Optics[Semray UV5000+, 385 nm]

Printing [sheetfed offset]

80 mm

50 mm

20 mm

0 mm



No Optics[Semray UV5000, 385 nm]

Primary And Secondary Optics[Semray UV5000+, 385 nm]

7/21/202024

AGENDA



CASE STUDY – SHEETFED OFFSET


Request › Reduce downtime› Increase turnaround› Print on heat-sensitive

substrates› Flexibility to print on different

formats› Speed is paramount (18.000

spm, approximately 300 m/min)› Performance delivery at a

working distance of 40-100 mm

7/21/202026

Development› Process validation tests› Machine integration and required

periphery flexibility› Latest version cures 400% ink

coverage + varnish with a single UV LED lamp (depending on application, inks, thickness, etc)

Solution› Instant curing, increasing turnaround› High power UV LEDs system with

secondary optics for high working distances

› Scalable width to fit in all presses› Complete system integration

› Instant on/off: 10%+ energy savings› Dimming: supply energy just where required › Format selection: + 50% savings

CASE STUDY – TILE RESIN COATING


Request › Replace outdated

mercury system› Print speed: 20 ft/min› Curing distance: 2 inches› Thickness of resin varies

requiring LED system to compensate for thickness

› Wavelength: 365 nm

Development› Trials at Heraeus lab and

OEM demo center› First demo test Semray

UV4103› Second demo test Semray

UV7000› Customer validation tests› Machine integration meetings

7/21/202027

Solution› Final trials runs at full

production speed› Radiometry validation› Flexibility of integration› 75% Energy and spare

parts savings

Many thanks for your participation.

heraeus-noblelight.com/[email protected]


Documents

MEETING CHALLENGES WITH HIGH POWER UV LED SOLUTIONS · Online Session: Meeting Challenges with High Power UV LED Solutions TOTAL REVENUE in 2019 22.4 bn € GLOBAL BUSINESS UNITS