Optimization of Plasma Pretreatment in Roll-to-Roll Processing for Ultra-High Web Speed Applications

Optimization of Plasma Pretreatment in Roll-to-Roll Processing for Ultra-High Web Speed Applications

Neil Morrison
Amat

Traditional magnetron glow discharge based plasma pretreatment processes are limited by a low ion dose and low ion energy.  This problem is exacerbated by the use of the high substrate transfer speeds typically used in the vacuum web coating industry.  Furthermore, fully oxygenated process chemistries cannot be fully exploited due to target poisoning effects.  Mid-frequency (MF) alternating current based pretreatment systems or ion beam based systems have therefore been developed to overcome these limitations and provide the ability to much more closely tune the pretreatment process to both the specific substrate in question and its surface chemical & surface structure based characteristics.  This includes operating in either heavily oxygen or nitrogen rich environments and the use of much higher operating power levels for higher dose, higher energy processing. The work described in this paper is based upon the experimental characterization of both high-power MF & RF based linear ion pretreatment sources, the demonstration of the experimental impact of ion dose on both the adhesive bond strength and in the case of vacuum metallization, the barrier performance of coated packaging substrates. Further discussion will be held on the impact of the process gas utilized for the respective pretreatment process.