Hughes Aircraft Company

Other

Vicente Soto

Gerald B Smith

Helen Congleton

Carol L Slaton

Angelo Koudounaris

Lead wires extending out from an electrical circuit device are removed from respective bonding pads to which they are bonded by a lateral shearing action. Shearing can be accomplished either unidirectionally, or with a bidirectional reciprocating movement. A shearing tool is provided with a single shearing projection for a unidirectional shearing, or with a pair of spaced shearing projections for bidirectional shearing. A vertical alignment is established between the tool and a first lead to be sheared, and this initial alignment is also used for shearing the other leads of the device. With the actual bond between a lead and its bonding pad occupying only a minor portion of the available surface area, a subsequent lead from a replacement device is bonded to the same bonding pad as the first lead by forming a new bond at a different site along the pad.

Method of reworking bonded lead wires

Apparatus for removing metallized leads bonded to metallized bond pads

Lead wires (4) extending out from an electrical circuit device (2) are shaped for engagement to a substrate (38,40) upon which the device (2) is placed by engaging the lead wires (4) at a location laterally spaced from the device (2), exerting a force on the lead wire (4) at the engagement location to bend it down to the substrate (38,40), and then applying an inward force on the bent lead wire (4) towards the device (2) to further bend the wire to the desired shape. The lead wire (4) is engaged by a forming tool (21,27,33) having a universal head that applies the inward force either by biting into the lead wire (4) with a sharp edge (26), or by moving a bearing wall (36) against the end of the wire (4). When the forming tool (21,27,33) is operated by a programmable wire bonding system, the wire forming operation can be integrated with the bonding operation by using the same forming tool (21,27,33 ) to perform both functions. A single tool can be used to accommodate many different types of circuit packages and lead wire configurations.

Universal apparatus for forming lead wires

An electrical circuit component is temporarily fixed to a temporary substrate. Electrical contacts on the component are interconnected with corresponding contacts on the test substrate by lead wires or ribbons using a bonding wedge that forms the lead wires into a gull-wing shape with central portions thereof formed adjacent to edge portions of the component. The component is subjected to a test procedure while fixed to the temporary substrate via signals applied to the contacts thereof. The lead wires are then severed near their connection to the temporary substrate, and the component with the remaining lead wire portions attached is removed from the test substrate. The lead wires are sufficiently stiff and/or are adhered to the edge portions of the component with an adhesive so as retain their shapes after removal of the component from the temporary substrate. The component is then adhered to a permanent device substrate, and the ends of the lead wires are bonded to corresponding contacts on the device substrate.

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Riverside, CA, United States of America

Vicente Soto