| 摘要 |
PURPOSE: To easily eliminate dross and spatter while maintaining a fine form of high precision without generating deformation after laser working, in the working method of a lead frame. CONSTITUTION: Both of the surfaces of a metal plate 1 are coated with resist films 2 resistant to electroworking. By laser irradiation, cutting trenches 3 penetrating the metal plate 1 are formed according to the form of a lead frame 100. By electroworking of the metal plate 1 after the laser working, the interface between the metal base and a working denatured layer of the metal plate 1 is selectively corroded (hole corrosion). Thereby not only the dross and spatter which have been a problem but also the working denatured layer 9 containing a resolidification layer, a thermal influence part, etc., formed on the side walls of the cutting trenches 3 are all eliminated. The resist film 2 is finally eliminated. |
