Vacuum deposition of high performance gas barrier materials for electronics applications

摘要

The subject of transparent gas barrier layers has been of substantial interest in recent years both for existing applications, such as food packaging, but also to develop extended capability for new high-performance products both in packaging and functional films. For many of these more recent technologies, it is the water vapour permeation rate that is the key parameter for improvement. Predicted required values vary between reports, but some examples include 10~0 - 10~(-2) gm~(-2) day~(-1) for advanced food or pharmaceutical packaging and organic thin film transistors (OTFTs), 10~(-3)-10~(-4) gm~(-2)day~(-1) for Dye sensitised solar cells (DSSC) and Vacuum insulation panels, and 10~(-5) - 10~(-6) gm~(-2)day~(-1) for OLEDs and excitonic (e.g. polymer) photovoltaics. When considering the requirement for gas barrier the projected lifetime of the component and its tolerance of local failure of the barrier should be considered. Coupled to any WVTR performance of course is the cost of materials and deposition (typically web speed), transparency and mechanical properties.