2012 11-27-masterclass-conductive-inks-sirris

Masterclass Future of Conductive Printing November 27, 2012 - Belgium

Sirris

Non- contact conductive printing with inkjet & AJP technology

Sirris the collective center of the belgian technology industry

2 Masterclass Future of Conductive Printing November 27, 2012

• Nonprofit organisation • Industry owned • Member organisation

“Increase the competitiveness of belgian technological companies through

technological innovations”

Mission

Technology domains

•Materials Engineering

•Production Technology

•Mechatronics

•Rapid Manufacturing

•Software Engineering & ICT

•Technology Coaching

Agenda

• Inkjet printing • Technology • Printing requirements • Clip results

• Aerosol Jet Printing

• Technology • Comparison with other techniques • AJP and Conductive inks • Applications


Inkjet printing

Powerful technique

• Digital printing - print at wish • High quality • Low cost • Small waste • Non contact/sensitive substrates • Working in ambient conditions • No masking • Flexible • Scalable page wide to R2R


With specific guidelines for the inks

• Fluid Evaporation The jetting fluid system must not dry at the nozzle / air interface.

• Viscosity Viscosity should be between 10-20 cP (1.0x10-2 - 2x10-2 Pa*s) at

operating temperature. The printhead can be heated up to 70ºC to lower the working viscosity if the fluid is viscous.

• Surface Tension Surface tension should be between 28 and 48 dynes/cm (2.8-4.8

N/m. High surface tension fluids (up to 60 dynes/cm) may be jetted with limited performance.

• Filtering In general, a filter is used to remove any large aggregates or

particles. In general, the particles in the fluid should be 1/100 the size of the nozzle.

• Degassing Removal of dissolved gas improves jetting and priming

characteristics of most fluids. Degas the fluid before loading into the fluid module. Degassing is especially helpful for aqueous-based fluids.

Technology


High speed No clogging Low resolution

Low cost High resolution Limited fluids

All fluids Long reliable life time High cost

Types of inkjet printers for functional materials

Labscale to semi-industrial Speed up to 30m/min

Printheads

Fujifilm Xaar

Konica Ricoh

… 1pL to 80pL


Ink specifications


Inkjet Aerosol Jet Flexo Screen

Resolution ~ 30µm ~ 10 µm ~ 100 µm ~ 100 µm

Viscosity <20 mPa.s (10 -20 preferably) 0,7 – 2500 mPa.s 300-1000 mPa.s 3000-50.000 mPa.s

Surface Tension 28-48 mN/m 25-30 mN/m (<45*) 25-30 mN/m (<45*)

Particle Size <0,2 µm Nano (micro) nano & micro nano & micro

Difficult ink development: narrow range for viscosity and nano-particles necessary

Inks


Silver inks • Low curing temperature • Close packing • High resolution • Plasma or wet-chemical nano-production • Limited volume • High Price

Copper inks • Lower price than Silver • Oxidation sensitive higher sintering cost • Small volumes

Commercial inks available for conductive printing


Company name ink type ink particle diam. wt conc. printer substrate drying/sinter technology dry thickness cnm %

Novacentrix metalon ICI-001 water based nano copper 143 8% ink-jet photo paper, coated PET Pulseforge UV flash 0.3-0.4Novacentrix Metalon ICI-003 nano copper oxide 143 10 Ink-jet polymer films Pulseforge UV flashIntrinsic Intrinsic CI Cu nano 45 12 Ink-jet paper,PET photonic curing 0,3-0,4Novacentrix Metalon JS-B15P Ag-nano 70 15 Ink-jet PET,Paper Pulseforge UV flashNovacentrix Metalon JS-B25P Ag-nano 75 25 Ink-jet PET,Paper Pulseforge UV flashNovacentrix Metalon JS-B35P Ag-nano 55 35 Ink-jet PET,Paper Pulseforge UV flashNanomas Technologies NTS 05IJ Ag nano 2-10 10-30 Ink-jet plastic film,Paper hot airAdvanced Nano products DGP 40LT-15C Ag nano 30-40 Ink-jet plastic films hot airNano-Gap NGAP FI Ag-4101 Ag-nano 40-60 30-60 Ink-jet paper hot airCabot CCI-300 Ag nano <200 20 Ink-jet PET,paper hot air 0,4

• Today limited to Ag and Cu for metal based inks • Others: PEDOT:PSS

• Future: graphene-based. Difficult development

Filtering

• Filtering of the inks • necessary if small nozzle cartridges are used • Nano-particles tend to agglomerate

• Wide variety of filters available

• Materials: PP,PES,PTFE,Nylon6,… • Different µ-structures • Ink dependent


Cellulose PVDF PC PES

Substrates

• Type of substrate to be used depends on application, curing and sintering conditions and the required conductivity of the printed circuit.

• Papers: good printability, good adhesion, solvents are absorbed quickly by the paper, fast drying but porosity of paper can have a negative effect on conductivity.

• Plastics: good printability, longer drying and curing time, adhesion can be a problem. No interference from substrate (no porosity). If curing and sintering are good optimal conductivity


Paper #

Sheet Resistance@ 150ºC/30min.

Sheet Resistance@ 150ºC /30min+180ºC/15 min.

Printed image quality

6 3.2 kΩ/ 151Ω/ Bad

7 9.4 kΩ/ 100Ω/ Good 8 82 kΩ/ 228Ω/ Good

9 14.5Ω/ 3.2Ω/ Good 10 1.05Ω/ 0.428Ω/ Good

Inkjet in CLIP- project


System properties • Dimatix DMP-2831

• Replacable cartridges

• 16 nozzles

• Single row

• 10pL (21 µm) en 1pL (9 µm)

Ink printing tests

• Nano-Silver based (monomodal, bimodal and trimodal)

• Nano-Cu based

CLIP results

• Comparison mono, bi and trimodal samples Bi and trimodal samples: combination of different nano-particle sizes Close Packing of particles better conductivity at low sintering

temperatures.


CLIP results

• Influence of drop spacing


CLIP results

• Influence of multiple layers


Conclusions

• Inkjet technology is mature and available for conductive printing

• Upscaling is possible to R2R with increasing printing speed • Bottleneck is the ink-development to fit the requirements • Cost reduction related to Cu-inks is not that high because nano-

particle production is driving factor • Sintering of Cu-based inks needs alternative for thermal sintering

• At low sintering temperatures

• Multimodal Ag-based inks show lower resistance • Less ink necessary for comparable conductivity as monomodal inks


Agenda

• Inkjet printing • Technology • Printing requirements • Clip results

• Aerosol Jet Printing

• Technology • Comparison with other techniques • AJP and Conductive inks • Applications


Non contact AJP technology


Aerosol Jet Printing (AJP) 300 CE

Printing of nano composed ink

©OPTOMEC

2 heads of deposition

Laser sintering technology by IR laser

Non contact AJP technology AJP Technology description

1 2

3

4

5

6

7

1 – Nitrogen input

2 – Ventury depression created

3 – Aspiration

4 – Mist created (1-5µm droplet)

5 – Mist is transported

6 – Sheath gaz input

7 - Printing and Deposition

Pneumatic atomisation

Masterclass Future of Conductive Printing November 27, 2012

20

Non contact AJP technology Available commercial ink

Conductors Nano Ag - UT Dots, Nanomas, Cabot, Nanosize, Harima, ANP... Nano Au - UT Dots, Nanomas, Harima Nano Pd - Nanomas Nano Cu Thick Film Au - Dupont

Conductive Polymer

PEDOT:PSS from H.C. Stark SW CNT - Brewer Science

OE Semiconductor

P3HT, PQT, SW CNT...

Resistor PTF Carbon - Asahi, Dupont Metal Oxide - Dupont

Dielectrics

UV Epoxy - Norland, Locktite, Summers... PMMA- Alpha Aesar, PVP - BASF Polyimide- Huntsman PTF Barium Titanate- Asahi Teflon- 3M, Dupont

Novel Materials

MicroCat – MacDermid, Nano Composite Polymers, Biomaterials...


21

Non contact AJP technology AJP Technology capabilities

- Minimum feature size (~ 10 µm) High resolution, high density of printed features.

- A very large range of printable inks (viscosity from 1 up to 2500 cP) (Conductive/ dieletric/ polymer conductor/ biomaterial / UV curable /…)

Large range of inks large range of applications, from electronics to biological material printing. - Direct printing technology - maskless

No need for a mask or any photolithography-based preparation of the substrate time and material saving.

- Local curing of inks by laser sintering

Instead of putting the complete substrate in an oven, local sintering of inks is made on-the-fly by a focused laser beam.

- 3D or flexible substrates are welcome

Controlled position in z-direction of the writing head wrt. substrate.


Non contact AJP technology Comparison (AJP/Inkjet/Screen Printing)


DS29 NANOGAP developed ink in the CLIP project

Typical commercial reference

Non contact AJP technology What about ink resistivity (CLIP Frame Work)

(1) Ink mist is compounded with nano conductive particle and solvent.

(2) Deposition with solvent envelop

(3) After evaporation (drying)

Interface grains

Thick

Thick

Thick=1 Thick~0,1

(4) After sintering

porous Then, while holes or porosity are present in the final conductive track, the resistivity still less than the pure resistivity value. The real question is “how fare is it from plain bulk material resistivity For all tested ink the best ratio is a factor ~“5” (which still the “state of the art” by printing technology)


Non contact AJP technology AJP application (CLIP frame work)

125

50

300 µm Each finger

Specification of this application : Resolution~= 150 µm easy for AJP Sheet resistance = 0.8 Ω/.

Could be easily done to 20-30 µm 10 µm is reachable in very specific conditions ..


Non contact AJP technology AJP application (CLIP frame work)

R=9,93 Mean Thickness measurement = 1.5 µm Width = 1 mm Length = 50 mm Sheet resistance calculation = 0.19 Ω/ Specification is respected but could be improved again


Non contact AJP technology Non contact 3D Application overview @ Sirris with AJP

Video


Non contact AJP technology Application overview @ Sirris with AJP

Substrate : Textile Ink : Silver

Substrate : Paper Ink : CNT

Substrate : Glass Ink : CNT

Substrate : Dielectric Ink : Silver

Substrate : PET flexible foil Ink : Silver

Substrate : Paper Ink : Copper

Substrate : COC Ink : PEDOT

Substrate : PMMA Ink : Silver

© Sirris © Sirris © Sirris © Sirris

© Sirris © Sirris © Sirris © Sirris


Conclusions

• Aerosol technology is dedicated for the future.

• (+) Direct printing on 3D substrate is easily done with AJP • (+) Due the “Aerosol” dynamic deposition, inks are easily printable • (+) AJP is very suitable for ink development.

• Large range of viscosity • Size particle from nano to µmicro • Pneumatic or ultrasonic atomization

• (+) AJP is equipped with Laser sintering. Curing by laser allow us to print and cure the deposition on low melting temperature substrates.

• (+) Fine line (10µm* width) deposition is one of the application of the AJP

• (-) The printing is dedicated for line printing (10µm to 100µm) not for large area printing (even in case of scaling up according to industrial requirement).


Thanks for your attention
