Piezo Printhead Technology
Course - GBP 795, Euro 995
Thursday 10th - Friday 11th July, 2008

imperial College, London, England

Conference registration

Location, directions and accommodation
COURSE FOCUS
With drop on demand piezo printheads becoming the key imaging technology for a wide new range of products and manufacturing processes, it is becoming vital to understand how these critical components work, and how to recognise when things are not as they should be even if you are just a user of OEM printheads.

Here Steve Temple will take you through the basics of piezo materials and their properties, how they are used as actuators within printheads, other aspects of printhead design, printhead operation, crosstalk, reliability and lifetime issues, and the special considerations for deposition and ink jet as a manufacturing process.

COURSE LEADER
Stephen Temple
Templetech

Impington, Cambridge, UK

Steve joined Cambridge Consultants Limited (CCL) in 1968 fresh out of Oxford University, with the intention of becoming a successful inventor. At that time, there was much talk of start-ups and of a vision of Cambridge as a centre of a new hi-tech revolution. Steve failed to join this bandwagon until 1990 when Xaar was founded.

In the meantime, he worked on and produced inventions for a huge diversity of industries and technologies: textiles (carpets and weaving); printing; new materials; space-sails and parachutes. Printing was a recurring theme during this time, and in 1987 together with others, he invented the Xaar technology. As soon as this became a spin-off prospect, he joined Xaar and was instrumental in its evolution from four people to a listed company of 300+ with sites in Cambridge, Huntingdon, Sweden, Japan and the US.

In 2007 he left Xaar with a view to starting a new venture and is currently exploring the potential for Rapid Manufacture using Ink Jet technology.

Course outline
Thursday 10th July 2008

10:00 - 11:00 am Registration
11:00 am Course begins

Piezo materials
• Fundamentals
- Petrovskite crystal
- Axes and modes
• Uses of piezo material
• Manufacturing methods
- Bulk sintering
- Tape cast
- Deposition
• Material properties
- k, d, e
- Curie temperature
- Soft versus hard
- Activation modes
• Direct mode
- Shear mode
• Problem areas and trade-offs
- Gearing
- Direct mode, multi-layers, bending, shear
- Fatigue
• Alternatives
- Thermal, capacitative, magnetic

1:00 - 2:00 pm Lunch

Piezo printheads
• Different piezo printhead architectures
- Roof mode (bender)
- Piston
- Moving wall
• Theory of operation
- Roof mode
- Moving wall
- Squeeze mode
- Acoustic
• Manufacturing methods
- Individual pieces
- Separate in situ
- Monolithic
- Thin film
• Channel structure manufacture
- Moulding
- MEMs
- Sawing

5:30 pm Adjournment
6:00 - 7:30 pm Reception

Friday 11th July 2008

9:00 am Course begins

Nozzles
• Importance
• Accuracy
- Geometric
- Defects
- Wetting
• Manufacturing methods
- MEMs
- Etching
- Laser Ablation

Driving piezo printheads
• Drive circuit design
• Thermal considerations
• Drive waveforms
• Frequency response
• Modelling behaviour
• Greyscale methods

Print Quality
• Greyscale versus resolution
• Crosstalk
- Pressure, acoustic & wetting
• Historical effects
- Wetting / Fluid
• Flight
- Aerodynamics & electrostatics
• Landing and splash down
- Direction, dot movement & dot gain

1:00 - 2:00 pm Lunch

Reliability
• Bubbles
• Dust
• Flooding
• Ink issues

Lifetime
• Electrical fatigue
• Mechanical fatigue
• Wear
• Damage

Designs for non-graphics printing
• Additional issues
- Drop size
- Ink characteristics
- Post-splash-down behaviour

Future for piezo technology
• Piezo materials development
- Single crystal
• Processing methods
- Moulding
- Deposition
• Operating limits
- Pumping
- Frequency versus drop volume

4:00 pm Adjournment