Technology

Scientific and Technological Objectives

Project Innovation

Innovative Concepts

The HI-RESPONSE project is based on the development of a highly innovative Pulsed Electro-Static Printing Technology. Among the various printing technologies Pulsed Electro-Static Printing represents a novel deposition technique capable of applying functional inks in a viscosity range, droplet volume and at a frequency currently not available for classical piezo based ink jet technologies, but bearing the fundamental capability to fulfil market requirements in various fields. Thereby Pulsed Electro-Static Printing technology is able to bridge the gap between high and low ink viscosities within on deposition system. The enhanced viscosity range of inks is able to prevent fundamental issues or significantly reduces effects like coagulation of particles as known for nano-particle inks for inkjet printing and Pulsed Electro-Static Printing enables the exploitation of functional inks to novel fields of applications.

The specific advantages of the HI-RESPONSE technology are summarised below:

  • Resolution (feature size):

    • Droplet volume down to 0.001 pL can be achieved in compared to 5-90 pL for commercial inkjet printers.
    • ≤1 µm resolution for a range of (pre-existing and novel) conductive, semi-conductive, insulating and other functional inks – At least one order of magnitude better than existing technologies.
    • 2,116 dpi achievable (potentially increasing to 10,000 dpi) compared to 50-300 for conventional ink-jet printing.
  • Viscosity:

    • Broader range of ink types (aqueous or non-aqueous liquids, conductive or insulating liquids (conductivities from negligible up to 10-6S/m)) can be deposited than conventional inkjet.
    • Viscosities from 1 to 10000cP already verified.
  • Engineering simplicity and reliability:

    • Does not require pump or actuator - a massive advantage over ink-jet printing systems that require a piezo-pump system.
    • Tight control of the droplet size, frequency and on/off mode.
    • Can operate with long throw distance (more than 10mm).
    • Very high drop on demand – 66kHz highest Drop on Demand frequency achieved to date.
    • The adoption of this technology in the deposition of functional materials will result in a much broader design space to be accommodated for the formulation of functional inks, than is possible with conventional inkjet.
    • As the system does not require a piezo-pumping system, a very high print channel density can be achieved since print channels can be arranged over a two dimensional surface, rather than being in a single print channel line (as is the case/limitation with ink-jet printing). In comparison to the other competing technologies on the market is shown in the table 1 below:
    • The Innovative Concepts in relation to the end-use applications


  • Automotive Antennae :

    • High conductivity Cu Fractals printed onto polymer substrates with conductivity >50% bulk.
  • Automotive contact sensors :

    • High conductivity Cu wiper encoders printed onto FR4 substrates with conductivity >50% bulk sequentially with a dielectric material.
    • Increased pulse from 12 to 48.
    • Reduced wear.
  • Printing of deep copper filled trenches for through silicon vias (TSV) for Silicon :

    • Copper filled trenches for TSV applications using printing of high solid content nano-Cu filled inks.
    • Good electrical conductivity.
    • Low mechanical stress.
    • Increased thermal stability.
    • Replacement of current electroplating manufacture – Which is expensive, slow and environmentally unfriendly.
  • Metal mesh ITO replacement for touch screens

    • Wire thickness of 1µm, one order of magnitude less than current printed meshes and better than world leading Chinese Academy (Nanchang O-Film) mesh based on complex structuring.
    • High conductivity Cu (>50% bulk) allowing surface resistance <100Ω/Sq. at 1µm wire thickness.
    • Transparency of >95% and elimination of other optical inconsistencies.
    • Sequential multi-layer / multi-material printing for x-, y- and dielectric layers.
    • Patterning of desired structure without additional post-processing steps
    • Reduction of current production times of up to 9 hours for large screen manufacture down to <30 minutes.
  • Metal mesh ITO replacement for OLED displays and lighting

    • Wire thickness of 1µm, one order of magnitude less than current printed meshes and better than world leading Chinese Academy mesh.
    • Sequential multi-layer / multi-material printing for x-, y- and dielectric layers.
    • Patterning of desired structure without additional post-processing steps.
    • High conductivity Cu (>50% bulk) allowing sheet resistance <5Ω/Sq.
    • Transparency of >95%.
  • Printed active pixels for OLED displays and lighting

    • Printing of active OLED materials for display and lighting applications at resolutions of <10µm allowing printing at 300dpi.
    • Increased material yield due to direct printing process with material usage of > 90%, current vacuum based processing technologies suffer from low material yield depending on the tool system, which is often reported to be between 10-50% at maximum.
    • Faster processing times.
    • Easier scalability to larger substrate size as compared to vacuum processing.
    • R2R production potentially achievable, easier and more cost effective than with vacuum techniques.
    • Potential to manufacture without need for inert atmosphere.
  • Mechanical stabilisation of Si-Wafers

    • Printing of ceramic ribs for strengthening of thin silicon wafers to achieve a resolution of 30 µm requires deposition of inks with a solid fraction of up to 10 Vol.-% and viscosity of > 10.000 cP which cannot be achieved by conventional inkjet printing.
    • Material will have similar coefficient of thermal expansion, thereby increasing temperature stability.
    • Increased thermal stability.
    • Process cost reductions.
    • Increased strength and temperature resistance.

Capabilities

  • Droplet volume down to 0.001 Pico litres
  • ESJET will enables 10,000 dots per inch (dpi)
  • Can deposit a wide range of viscosities from 1 to 10,000 centipoise