Electroformed and chemical milled bumped tape process

摘要: A process for producing a copper lead frame tape in which the individual fingers of are provided with gold plated bumps. foil is dry film photoresist on both sides and initially processed to provide openings one side resist electroforming end products directly foil. Further processing produces other locations than opposite first bumps whereby following chemical milling exposed yields plurality fingers, each consisting an integral bump/copper arrangement. The step made possible by novel double-cell electroplating method relatively high-impedance ion path connects two cells. Bump heights as much 0.0013 inch or greater produced disclosed process, uniformly excellent quality.