1. HP Thermal Bubble Jet Printer
Maran Ma
Yuan Fang
Ramneet Singh

2. Outline History of Printer Technologies HP Bubble Jet Printer
HP Print Head Fabrication
Print Head Packaging & Circuitry
Performance Analysis
Conclusions

3. History 1878 – Lord Rayleigh – droplet breakup
1960 – Continuous ink-jet - stream broken into droplets via pressure wave pattern

4. History (cont’d)
1979 – Canon develops drop-on-demand thermal bubble-jet
1984 – HP produces first commercial bubble-jet called ThinkJet

5. HP’s Bubble-jet Advantage
HP’s print head is disposable – doesn’t sacrifice quality
Better quality due to frequent replacement
Allows for up to 4800x ppm
Allows the use of pigmented ink for increased precision and superior fade performance

6. Video clip on HP Cartridge

7. Print Head Functional Requirements
Store ink for each nozzle
Heat ink drop via heater resistor
Release ink at desired quantity & position

8. HP Print Head Fabrication
Integrated fabrication process, facilitates critical alignment of:
Ink reservoir
Heater resistor
Orifice plate
Reusable substrate: silicon or glass, with photoresist islands
Orifice plate: nickel, via electroforming
Photoresist island
Reusable substrate
Orifice plate

9. HP Print Head Fabrication (cont’d)
First insulating barrier: prevent shorting of resistor/conductor with orifice plate
Heater resistors: narrow region of conductor
R = Rs (L/A)
Heater resistors – plan view
Insulating barrier layer
Heater resistor
Lead-in conductor
C-shaped heater resistor
Lead-in conductor

10. HP Print Head Fabrication (cont’d)
Second insulating barrier: prevent corrosion of resistor/conductor by ink
Seed layer: sputtered metal, etched to C shape
Ink reservoir wall: nickel, via electroplating
Substrate removal: peeling to unplug orifices
Second insulating layer
Insulating layer
Seed pad
Wall
hole

11. HP Print Head Fabrication (cont’d)
Table 1. HP Bubble Jet print head fabrication procedure summary [8]
Layer
Suitable Material
Deposition Process
Thickness [um]
Substrate
Oxidized Silicon/ Glass
Orifice Plate
Nickel
Electroforming
20-75
Insulating Layer 1
Silicon Dioxide
/Silicon Nitride
/Silicon Oxynitride
PECVD
/LPCVD
1-3
Resistor & Conductor
Polysilicon
/Tantalum Silicide
/Gold
Sputtering
/PECVD
Insulating Layer 2
Silicon Nitride &
Silicon Carbide
LPCVD
0.5-2
Seed Layer
/Titanium
/Chromium
Barrier
Electroplating
10-75

12. HP Print Head Fabrication (cont’d)
Print head structure – plan view: ink flow channels along A
MEMS fabricated print head structure prior to assembly with cartridge
Lead-in conductor
C-shaped heater resistor
C-shaped reservoir wall
Orifice (nozzle)
Hole
Ink reservoir
Wall
Second insulating barrier layer
First Insulating barrier layer
Heater resistor
Lead-in conductor
Orifice plate
Seed pad

13. Print Head Packaging & Circuitry
Print head soldered to ink supply chamber wall
Electrical contact bonded to exposed conductors
Electrical contact with lead-in conductor
Dome of C-shaped ink reservoir wall
Ink supply chamber
Ink supply chamber wall
Electrical lead for circuit interfacing
Lead-in conductor

14. Print Head Packaging & Circuitry (cont’d)

15. Print Head Packaging & Circuitry (cont’d)

16. Performance Analysis
Piezoelectric printers are susceptible to nozzle-clogging
TIJ use pigmented ink and pressure nozzle ejection
Piezoelectric vs TIJ vs Laser print on plain paper
TIJ vs Piezoelectric dots

17. Colour Printing dpi is not the best measure of performance
Rapid ejection of small dots is the key to quality printing (dps)
HP’s TIJ has a higher throughput
Smaller drop fluid chamber – more nozzles and higher firing frequency
Epson PM dpi, 65microns
HP 2000C 600 dpi, 45microns

18. Colour Printing (cont’d)
Piezoelectric versus TIJ drops-per-second comparison

19. Conclusions
The Bubble jet print head is fabricated using MEMS technology
Fabrication processes include: PECVD, LPCVD, photolithography, etching and sputtering
Integrated design of the print head can increase reliability and reduce cost

20. References
[1] “Progress and Trends in Ink-jet Printing Technology”, Journal of Imaging Science and Technology, volume 42, Number 1, Janurary/Feburary 1998 [2] Vince Cabill, “Introduction to Digital Printing Technology”: [March ] [3] “HP Business Inkjet 2800 Printer Series, Technical Specifications”, Hewlett-Packard Development Company [August 2005] [4] “Piezoelectric Process”, PDS Consulting: [May 8, 2006]. [5] David B. Wallace, Donald J. Hayes and Christopher J. Fredrickson, "Ink-Jet Based Fluid Microdispensing for High Throughput Drug Discovery," March 2008, [6] Inkjet Workshop, “Tutorials – Definitions,” March 2008, [7] Stephen D. Senturia, Microsystem Design. New York: Springer, [8] Eldurkar V. Bhaskar and Marzio A. Leban, “Integrated Thermal Ink Jet Printhead and Method of Manufacture” US Patent , July 11, 1989 [9] C. S. Chan and Robert R. Hay, “Barrier Layer and Orifice Plate for Thermal Ink Jet Printhead Assembly” US Patent , September 15, 1987 [10] Richard A. Murray, “Printer Ink Cartridge with Drive Logic Integrated Circuit” US Patent , July 8, 1997

21. Questions?