International Business Machines Corporation

Tamar A Sholtes

Charles Gerard Woychik

Kishor V Desai

Robert H Katyl

Harold Kohn

Vilakkudi G Veeraraghavan

Nelson P Franchak

Ronald Walker Gedney

Endwell

A package for mounting I/C chips onto a circuit board is provided. The chip has a surface array of input/output pads on one side which forms a footprint. A carrier is formed of an organic dielectric material having opposite surfaces. A first set of bonding pads is formed on one surface of the chip carrier and arranged to correspond with the chip footprint. A first set of solder ball connections connects the input/output pads on the chip to the first set of bonding pads on the chip carrier. A second set of bonding pads is formed on the other surface of the chip carrier forming a second set of bonding pads. Electrically conducting vias extend through the chip carrier connecting the first set of bonding pads to the second set of bonding pads. An organic circuit board having a coefficient of thermal expansion similar to the chip carrier having electrical connector sites is provided, the sites are arranged in a pattern corresponding to the pattern of the second bonding pads on the chip carrier. A second set of solder ball connections connect the pads of the second set of bonding pads on the chip carrier to the connection sites on the circuit board.

IC chip attachment

Method and apparatus are disclosed for mounting a flexible film semiconductor chip carrier on a second level electronic package. The resulting electronic packaging structure includes electrically conductive spacers, such as solder balls or solder coated copper balls, which electrically interconnect outer lead bonding pads on the flexible film semiconductor chip carrier and corresponding bonding pads on the second level electronic package, and which physically support the flexible film of the semiconductor chip carrier substantially in a plane above the surface of the second level electronic package. This electronic packaging structure is made using a special assembly fixture comprising a base plate, a pressure insert with a resilient member, and a top plate. The flexible film semiconductor chip carrier with the spacers attached thereto is placed over the resilient member of the pressure insert which is clamped together with the second level electronic package between the top and base plates. Then, this assembly is heated to reflow the solder of the spacers, and the assembly fixture is disassembled,; leaving the flexible film semiconductor chip carrier mounted on the second level electronic package with the flexible film of the carrier having a planar geometry as desired.

Method and apparatus for mounting a flexible film semiconductor chip

Method and apparatus are disclosed for mounting a flexible film semiconductor chip carrier on a second level electronic package. The resulting electronic packaging structure includes electrically conductive spacers, such as solder balls or solder coated copper balls, which electrically interconnect outer lead bonding pads on the flexible film semiconductor chip carrier and corresponding bonding pads on the second level electronic package, and which physically support the flexible film of the semiconductor chip carrier substantially in a plane above the surface of the second level electronic package. This electronic packaging structure is made using a special assembly fixture comprising a base plate, a pressure insert with a resilient member, and a top plate. The flexible film semiconductor chip carrier with the spacers attached thereto is placed over the resilient member of the pressure insert which is clamped together with the second level electronic package between the top and base plates. Then, this assembly is heated to reflow the solder of the spacers, and the assembly fixture is disassembled, leaving the flexible film semiconductor chip carrier mounted on the second level electronic package with the flexible film of the carrier having a planar geometry as desired. The spacers may be attached to the flexible film semiconductor chip carrier using a special template having a pattern of openings corresponding to the pattern of outer lead bonding pads on the flexible film semiconductor chip carrier.

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Endicott, NY, United States of America

Tamar A Sholtes