METHOD AND APPARATUS FOR SURFACE TREATMENT

摘要

A method and apparatus for surface treatment, wherein a workpiece is exposed to an activated gas containing nitrogen and water at an atmospheric pressure to modify the surface of the workpiece. To improve wettability of a soldered lead frame (12), oxygen is fed from a gas supply (619) to a plasma generator in a surface treatment unit (30) through a first pipe (657). Nitrogen is fed from the gas supply (619) into a container (659) of pure water (660) through a second pipe (658), and the wet nitrogen is introduced to the plasma generator in the surface treatment unit (30). The gas supplied into the plasma generator is excited and decomposed by an electrode to which a D.C. voltage or a low-frequency A.C. voltage of not higher than 50 KHz is applied, and a plasma containing nitrogen oxides is generated. An IC (10) is exposed to this plasma for the surface treatment of the lead frame (12). Oxides on the surface of the lead frame (12) are reduced or their oxides are substituted by nitrogen oxides, and the surface of the lead frame (12) is modified.