International Business Machines Corporation

Siemens Aktiengesellschaft

Stephen G Starr

William C Ward

H Ward Conru

Douglas W Phelps, Jr

Jens G Pohl

Eric Jeffrey White

Ronald R Uttecht

Albert J Gregoritsch, Jr

Gary H Irish

William J Slattery

Sheldon C Rieley

Francis J Pakulski

Francis E Froebel

Harold W Conru

Gordon C Osborne, Jr

Robert J Redmond

John Conrad Kutt

Friedrich A Karner

Stephen E Gons

Robert Henry Zalokar, Jr

Judith A Chase

A lead frame having a plurality of metallic conductors with each conductor having a coined or stamped region near its proximal end but spaced therefrom to provide pressure points to assure substantial even joining of the conductor to semiconductor chip via an insulative adhesive medium. The lead frame, when mounted on the active face of a semiconductor chip, has wires connecting terminals on the major active surface of the semiconductor chip to the bands on selected lead frame conductors. The lead frame on the semiconductor chip and the wires which connect the semiconductor chip terminals to the bands of selected lead frame conductors are then encapsulated with a suitable insulative material to form a semiconductor module or package.

Semiconductor lead frame

A process of Pb/Sn evaporation eliminates haloes in the manufacture of solder bump interconnects. This robust process of forms solder bump interconnects and reduces critical molebdnum mask sensitivity. Vacuum evaporation through which Pb/Sn C4 pads are deposited is performed by maintaining parallel temperature gradients between the molybdenum mask and silicon wafer, thus resulting in elimination of connecting haloes and yield losses.

C4 Pb/Sn evaporation process

A lead on chip (LOC) semiconductor leadframe package provides notched lead-fingers to eliminate mechanical shear-stress at the peripheral edge of a semiconductor chip. Opposite rows of substantially flat cantilevered lead-fingers are attached by double-sided adhesive tape in thermal contact with the active face of a chip. The lead-fingers are routed in personalized paths over the face of the chip to cover a large surface area to aid heat dissipation. All wirebond connections between the lead-fingers and the chip are made at a centerline connection strip running down the center of the chip. Each of the cantilevered lead-fingers has a notched portion positioned directly over the vulnerable peripheral chip edge to reduce thermal, mechanical shear-stress. Additionally, since corrosion typically follows a lead path, the notch provides increasing path length to prevent corrosive ingress over the chip face.

Personalized area leadframe coining or half etching for reduced

A lead on chip (LOC) semiconductor leadframe package provides notched lead-fingers to eliminate mechanical shear-stress at the peripheral edge of a semiconductor chip. Opposite rows of substantially flat cantilevered lead-fingers are attached by double-sided adhesive tape in thermal contact with the active face of a chip. The lead-fingers are routed in personalized paths over the face of the chip to cover a large surface area to aid heat dissipation. All wirebond connections between the lead-fingers and the chip are made at a centerline connection strip running down the center of the chip. Each of the cantilevered lead-fingers has a notched portion positioned directly over the vulnerable peripheral chip edge to reduce thermal, mechanical shear-stress. Additionally, since corrosion typically follows a lead path, the notch provides an increasing path length to prevent corrosive ingress over the chip face.

This is a semiconductor chip in which the conductive path between the chip and the lead frame via wires can be easily and reproduceably improved. This is accomplished by improving the bond between the wires and the lead frame members to which the wires are joined and by creating additional contacts between each wire and its respective lead even if the bonded contact breaks or fails at or immediately adjacent to the bonding point. This is accomplished by placing an insulating layer on the active surface of each chip, carrying input and output bonding pads thereon, to which lead frame conductors have been connected by bonding wires. The insulating layer is a thermosetting adhesive and is placed over the lead frame, the bonding wires and the active face of the semiconductor chip so that when a lamination force is applied to the insulating layer the wires will be crushed and held against their respective pads and against the respective leads to which they are connected and the active face of the semiconductor protected by the adhesive bonding thereto. In this way greater contact between the wires and the leads is enhanced and defects or failure in conductivity therebetween reduced or eliminated.

Planarized thin film surface covered wire bonded semiconductor package

A method of making a semiconductor chip in which the conductive path between the chip and the lead frame via wires can be easily and reproduceably improved. This is accomplished by improving the bond between the wires and the lead frame members to which the wires are joined and by creating additional contacts between each wire and its respective lead even if the bonded contact breaks or fails at or immediately adjacent to the bonding point. This is accomplished by placing an insulating layer on the active surface of each chip, carrying input and output bonding pads thereon, to which lead frame conductors have been connected by bonding wires. The insulating layer is a thermosetting adhesive and is placed over the lead frame, the bonding wires and the active face of the semiconductor chip so that when a lamination force is applied to the insulating layer the wires will be crushed and held against their respective pads and against the respective leads to which they are connected and the active face of the semiconductor protected by the adhesive bonding thereto. In this way greater contact between the wires and the leads is enhanced and defects or failure in conductivity therebetween reduced or eliminated.

Method of making a planarized thin film covered wire bonded

A plastic encapsulated semiconductor package in which the connecting lead frame members are deposited over the surface of the device together with a covering ground plane so as to provide enhanced electrical and thermal coupling of the members and the device and so reduce the signal to noise ratio by a factor or greater than three over that available in other similar plastic encapsulated packages while simultaneously improving the transfer of heat out of the package. In particular, a lead frame having a plurality of conductors is attached to a major active surface of a semiconductor chip via a ground plane which, in the preferred embodiment, is a multilayered structure containing an insulated integral, uniform ground plane positioned between the lead frame and the chip and adhesively and insulatively joined to both of them. Wires connect terminals on the major active surface of the semiconductor chip to the ground plane and to selective lead frame conductors. The lead frame, the ground plane structure, the semiconductor chip, and the wires which connect the semiconductor chip terminals to the ground plane and to selected lead frame conductors are encapsulated with a suitable insulating material to form a semiconductor module or package.

Semiconductor package with ground plane

A compression bond is formed between a gold or gold alloy wire and lead/tin solder by forming a head on the wire and forcing the head into a pad of the solder by thermosonic, or thermocompression, or ultrasonic compression bonding techniques. This forms a gold/tin intermetallic compound which in turn forms the bond. The head of the wire is maintained out of contact with any underlying surface, and surrounded by the solder.

Method of bonding gold or gold alloy wire to lead tin solder

A system of single lead clamping and bonding in the assembly of integrated circuit devices. A capillary bonder has a clamp member rotatably mounted around the capillary for movement with the bond head. The clamp is moveable vertically to contact and clamp a terminal to be bonded. The clamp is rotatable to orient itself with respect to the terminal and the fine wire. The capillary and clamp move under computer control to make a series of bonds, typically between lead frame fingers and terminals on a semiconductor device.

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Essex Junction, VT, United States of America

Stephen G Starr