Method of making foil based semiconductor package

Abstract

The present inventions relate to methods and arrangements for using a thin foil to form electrical interconnects in an integrated circuit package. In one embodiment, a foil carrier structure is formed by ultrasonically bonding portions of a conductive foil to a metallic carrier. The bonded portions define panels in the foil carrier structure. In some embodiments, the foil carrier structure is cut to form multiple isolated panels that are sealed along their peripheries. Each isolated panel may be approximately the size of a conventional leadframe strip or panel. As a result, existing packaging equipment may be used to add dice, bonding wires and molding material to the panel. The ultrasonic welding helps prevent unwanted substances from penetrating the foil carrier structure during such processing steps. After the carrier portion of the molded foil carrier structure is removed, the structure is singulated into integrated circuit packages. Some embodiments relate to methods that utilize some or all of the aforementioned operations. Other embodiments relate to arrangements used in the above processes.