Semiconductor lead structure and assembly and method for fabricating same

• Main Authors: BEYERLEIN; FRITZ W, DREES; JOSEPH M
• Format: Patent
• Language: English
• Published: 31.05.1977
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; SEMICONDUCTOR DEVICES; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

A lead structure formed from a sheet of electrically conducting material having a plurality of spaced integral lead arrays formed therein with each of the arrays comprising a plurality of first leads formed from the sheet material in one region thereof and being integral with the sheet with each of the leads being cantilevered and having inner extremities which are free and positioned in a predetermined pattern. Portions of the first leads adjacent the free ends are convoluted. A semiconductor body having at least portions of an electrical circuit formed therein and with contacts in a predetermined pattern carried by the body and lying in a common plane is secured to each of the arrays with the contact pads being bonded to the inner extemities of the first leads. A first encapsulating means is provided for encapsulating the semiconductor body and the inner extremities of the first leads with the outer extremities of the first leads being free of the first encapsulating means. After the first encapsulation, the outer extremities of the first lead are separated from the sheet of material. A plurality of spaced second leads are then secured to the outer extremities of the first leads. A second encapsulating means is then provided for encapsulating the first encapsulating means, the outer extremities of the first leads and the inner extremities of the second leads with the outer extremities of the second leads being free.