HIGH VACUUM ENVIRONMENT Sheila Hamilton Teknek Limited Issue - PowerPoint PPT Presentation

SUBSTRATE CLEANING IN A HIGH VACUUM ENVIRONMENT Sheila Hamilton Teknek Limited

Issue • Particles of contamination on substrates cause defects in coating, printing, lamination and vacuum deposition processes used in Flat Panel display manufacturing • Defects cause significant yield loss • Removal of particles is essential for high functionality and reliability IMID 2013 2

Technology Drivers • Films are getting thinner - more difficult to process • Coatings are getting thinner – even nanoscale particles can • penetrate the entire thickness of the coating causing pinholes • No air or wet systems can be used in vacuum environments • Smaller particles can now cause defects • Barrier properties are more demanding IMID 2013 3

Challenges • Need a cleaning system which can operate under vacuum • Needs to be able to remove very small particles • Cannot use air or liquid for cleaning • Must not alter the surface energy • Must not outgas IMID 2013 4

PPT 7 / 21 Contact Cleaning Technology The Teknek Cleaning Core IMID 2013 5

Cleaning Technologies IMID 2013 6

Defect reduction in optical coating IMID 2013 7

IMID 2013 8

Pinhole reduction in metallised film Average Pinhole 70 Pinhole Density (>5µ) / cm² (x100) Density of commercially available metallised 60 polyester film 50 40 30 20 10 0 No cleaning CRC Vacuum Plasma Cleaning Operation IMID 2013 9

Outgassing Test • Scud Vacuum System 032 • 2 small rollers • 2 sheets adhesive • Pumped down to 1E-7 mbar • Time in vacuum 66 hours • Each sample weighed before and after. IMID 2013 10

Ultracleen RGA IMID 2013 11

Ultracleen Outgassing IMID 2013 12

Nanocleen RGA IMID 2013 13

Adhesive Roll RGA IMID 2013 14

Cleaning Efficiency Test roller vacuum weight weight Differen roller condition adhesive sheet condition before after ce [g] nanocleen ambient ambient 4.31 4.57 0.26 1 weekend in vac (0.1 mbar) 4.31 4.54 0.25 18 hours in high vac (1 e-6 mbar) 4.3 4.55 0.25 1 weekend in vac (0.1 mbar) ambient 4.31 4.57 0.26 1 weekend in vac (1 e-6 mbar) ambient 4.3 4.55 0.25 nanocleen ambient ambient 4.31 4.6 0.26 ambient ambient 4.3 4.55 0.25 IMID 2013 15

AREAS OF APPLICATION • After stripping of protective film to remove possibility of static induced recontamination • Immediately prior to sputtering to remove any particles deposited from the walls of the chamber • Before rewind to stop particles imprinting on the layer below or fracturing the film • Cleaning the protective film at rewind prior to application to stop damage to the coating IMID 2013 16

IMID 2013 17

Benefits • Teknek technology can now – Remove particles down to 100 nm – From all types of substrates – As thin as 15 microns – In both sheet and roll format – At speeds from 1m/min to 300m/min – In a high vacuum environment – Without silicone – Gives significant yield improvements IMID 2013 18

Acknowledgements • European Funding Programme FP7 Clean4Yield project • The Holst Institute, Eindhoven • The Technical University of Dresden IMID 2013 19