| 摘要 |
A method and apparatus are provided for use in for manufacturing dual interline semiconductor packages including lead frame assemblies, for later subjection to soldering operations, in the making of printed circuit boards, and the like, wherein the surface contaminants and impurities including plastics residue, dust, dirt, oil, grease, products of oxidation such as oxides and sulfides, and other impurities such as CF4, and the like are removed or cleaned, particularly from lead pins 87, through a highly efficient, low cost, dry reverse sputtering operation. Substantially all contaminants are removed resulting in increased process efficiency, a higher reliability in product, and a much more effective and high integrity solder bond than was possible with prior mechanical and chemical cleaning techniques. The method is carried out by enclosing the package, including encapsulation 86 And lead pins 87 within an evacuable container 53 and connecting the package to a support 68 electrically connected to be the cathode, introducing an ionizable gas after evacuation of the chamber 53 and applying a voltage between the anode and the cathode to cause a discharge or plasma between the electrodes and to cause a flow of positive ions towards the parts to be cleaned 87. An alternative apparatus includes a cathodic mask (135; Fig. 4) and a non-conductive mask (132). <IMAGE> |
