Method of manufacturing electrical contacts, using a sacrificial member
Patent 5476211 Issued on December 19, 1995. Estimated Expiration Date: 
November 16, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 16, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3373481 3460238 3509270 3616532 Fabrication of circuit packages using solid phase solder bonding Fabrication of a printed circuit board with metal-filled channels Method for forming elongated solder connections between a semiconductor device and a supporting substrate Compliant interconnection and method therefor Chip mounting device Chip carrier mounting device InventorAssigneeApplicationNo. 152812 filed on 11/16/1993US Classes:228/180.5, Wire bonding29/840, By metal fusion29/843, By metal fusion bonding228/199, With subsequent treating other than heating of bonded parts and/or filler material257/E21.503, Encapsulation of active face of flip chip device, e.g., under filling or under encapsulation of flip-chip, encapsulation perform on chip or mounting substrate (EPO)257/E21.509, Involving soldering or alloying process, e.g., soldering wires (EPO)257/E21.511, Mounting on insulating member provided with metallic leads, e.g., flip-chip mounting, conductive die mounting (EPO)257/E21.512, Right-up bonding (EPO)257/E21.525, Procedures, i.e., sequence of activities consisting of plurality of measurement and correction, marking or sorting steps (EPO)257/E23.021, Bump or ball contacts (EPO)257/E23.024, Wire-like arrangements or pins or rods (EPO)257/E23.068, Additional leads joined to metallizations on insulating substrate, e.g., pins, bumps, wires, flat leads (EPO)257/E23.078, Flexible arrangements, e.g., pressure contacts without soldering (EPO)257/E25.011, Devices being arranged next and on each other, i.e., mixed assemblies (EPO)257/E25.029, Devices being of two or more types, e.g., forming hybrid circuits (EPO)427/117Wire conductorExaminersPrimary: Bradley, P. AustinAssistant: Knapp, Jeffrey T. Attorney, Agent or FirmInternational ClassesB23K 031/02B23K 101/38 AbstractA method for manufacturing raised contacts on the surface of an electronic component includes bonding one end of a wire to an area, such as a terminal, of the electronic component, and shaping the wire into a wire stem configuration (including straight, bent two-dimensionally, bent three-dimensionally). A coating, having one or more layers, is deposited on the wire stem to (i) impart resilient mechanical characteristics to the shaped wire stem and (ii) more securely attach ("anchor") the wire stem to the terminal. Gold is one of several materials described that may be selected for the wire stem. A variety of materials for the coating, and their mechanical properties, are described. The wire stems may be shaped as loops, for example originating and terminating on the same terminal of the electronic component, and overcoated with solder. The use of a barrier layer to prevent unwanted reactions between the wire stem and its environment (e.g., with a solder overcoat) is described. Bonding a second end of the wire to a sacrificial member, then removing the sacrificial member, is described. A plurality of wire stems may be formed on the surface of the electronic component, from different levels thereon, and may be severed so that their tips are coplanar with one another. Many wire stems can be mounted, for example in an array pattern, to one or to both sides of electronic components including semiconductor dies and wafers, plastic and ceramic semiconductor packages, and the like.Other References
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