| 摘要 |
PROBLEM TO BE SOLVED: To mass-produce lead frames for integrated circuit chips to which an expanding property and a soldering property are added without requiring an expensive product process, by including an aluminum or aluminum alloy unit having a surface which is so reformed as the expanding property and the soldering property to be added. SOLUTION: The thickness of a sheet 101 as an aluminum alloy unit for a semiconductor lead frame is 100 to 250 μm. Next, a zinc layer 102 is so formed to cover the aluminum surface without space by a thin film and reliable contact of a following nickel layer with aluminum is established. A first nickel layer 103 is coated in order for attached solution not to electro-chemically react the zinc layer 102. Next, an alloy layer 104 made of rare metal and nickel is coated and an electrically plated nickel layer 105 is coated. Additionally, two nickel layer and thin nickel alloy layers 106 are formed and a most outer layer 107 is formed to protect the nickel surface from oxidation. |
