| 摘要 |
PURPOSE:To cut down the cost of the titled lead frame by a method wherein a precious metal plating layer is selectively formed in such a manner that it is relatively thickly formed at the die-bonding part and formed as thin as possible at the wire bonding part. CONSTITUTION:The part where a plating layer will be formed is locally exposed at the central main part of a lead frame in advance, and a mask is provided on the other part. A gold plated layer is formed as thin as 0.1mu or thereabout by spraying a plating solution using a nozzle. Then, the mask is made larger, a die- bonding part 2 alone is exposed, a plating solution is sprayed, and the above- mentioned part is finished in the thickness of 0.3mu or thereabout. Thus, the thickness of the gold-plated layer is varied between the die-bonding part and the wire-bonding part. |
