| 摘要 |
PURPOSE: To prevent the diffusion of Cu ions into a polyimide film by forming a very thin polyimide film on a copper circuit before polyimide varnish is applied. CONSTITUTION: When a polyimide pattern is formed on a copper wiring, polyimide varnish is applied on the copper wiring and prebaked to form a prebaked film (1) of <=100nm thickness. Polyimide varnish is then applied on the prebaked film 1 and prebaked to form a prebaked film (2). This prebaked film 2 or a film formed by curing the film 2 is patterned. The polyimide varnish (1) is, e.g. a precursor of nonphotosensitive polyimide, a precursor of photosensitive polyimide or soluble polyimide. The prebaking processes are usually carried out with a hot plate or a hot air oven at 60-120 deg.C. |
