| 摘要 |
A method is for processing a leadframe and wirebond sites for use in a moulded package. Before being moulded to form the package, the wirebond sites are selectively plated with a suitable contact material and then with a protective material. After moulding the wirebond sites are etched to remove the protective material and expose the contact material. The wirebond surface is plated with gold as the contact material. The contact material is covered with copper as the protective material. The etchant comprises 10% ammonium hydroxide and 10% HCl. A cross section of a copper alloy leadframe (18) has wirebond sites (12) which are plated with a plated layer of gold (22) to form the bond pads for the wirebond contacts. A protective layer of copper (24) is plated only on protective material (22). A conventional process is used to encase the leadframe with a moulded housing (16) and part of this moulding (26) coats layer (24). An etchant which pref. etches protective layer (24) w.r.t. the remaining leadframe material is then used to remove protective layer (24) and moulding material (26) adhering to it to leave a clean contact layer (22). |
