FORMATION OF PROTECTING FILM

摘要

PURPOSE:To improve the corrosion resistance and abrasion resistance of a ferromagnetic metallic thin film by evaporating a target consisting of a polymer contg. an imide bond in its main chain by impingement of inert gas ion and depositing the same on a substrate surface. CONSTITUTION:A heat resistant polymer such as polyimide, polyester imide or polyamide imide contg. the imide bond expressed by the formulaIin its main chain formed to a film shape or baked as a coating film on an Al plate is used as a target. The above-mentioned target is evaporated by ion impingement in an inert gas and is deposited on the surface of the substrate to be protected. Namely, the surface is sputtered. This method is particularly suited for forming a protecting film on a ferromagnetic metallic thin film directly or via a non- magnetic layer, and improves the corrosion resistance of the metallic thin film and the abrasion resistance against a magnetic head considerably.