摘要 |
A method of coating a copper substrate comprises the steps of: anodically microsmoothing the copper substrate in an acid bath to provide a substantially smooth surface; electrocoating the microsmoothed substrate with a pin hole free nickel film having a thickness of between about 2.5 microns to about 12.5 microns; single step, non-aqueous electrocoating the microsmoothed, nickel coated substrate with a pin hole free polyamic acid polymer, and curing the polyamic acid coating to form a polyimide film free of copper ion contamination. |