Lead Frames

Lead frames are thin metal strips composed commonly of copper or copper alloys (e.g. CA194), and occasionally of Tin-Nickel alloys (e.g. Kovar), and are typically plated with Silver or a combination of Gold, Fold-Silver alloy, Palladium & Nickel. These strips are etched in repeating patterns to enable them to be cut and formed into individual frames, that are used to connect silicon based integrated circuits to printed circuit boards. Semiconductor chips are then bonded to an encapsulated lead frame and the entire assembly soldered onto a PCB. Plated layers are applied primarily to assure corrosion resistance and solderability.