Lsi Logic Corporation

Karla Y Carichner

Dexin Liang

A leadframe having individual bond fingers incorporating two or more alternate bonding areas. In one embodiment, conventional bond fingers having bonding areas in an outer row are augmented to include an additional conductive trace or intermediate portion terminating in a bonding area that is in general alignment with an inner row of bonding areas. Likewise, bond fingers having bonding areas in an inner row are enlarged to include an alternate bonding area that is in general alignment with the outer row of bonding areas. In another embodiment, bond fingers are arranged to provide multiple rows of closely-spaced staggered bonding areas to reduce bonding pitches. By providing alternate bonding areas in individual bond fingers, the manufacturing rules addressing staggered bond wire placement can be followed more readily, while simultaneously permitting the most convenient bond fingers to be utilized. The invention thereby adds significant flexibility to current staggered bonding techniques, and allows for a reduction in the size of many semiconductor dies.

Integrated circuit package having bond fingers with alternate bonding

A ball grid array package (BGA) according to the present invention has an interposer between a bond pad on the lower surface of the substrate and the solder ball. The interposer has a conductive portion in contact with the bond pad surrounded by a nonconductive or insulating portion. The conductive portion in contact with the bond pad is sufficiently constrained from widening during a subsequent reflow process by the presence of the nonconductive or insulating portion. The contact with the bond pad is sufficiently small to allow traces to pass near the bond pad substantially directly en route to another bond pad. The nonconductive portion also prevents subsequently-applied encapsulant from coming in contact with and contaminating the bond pad. The elevated surface of the interposer, i.e. the surface of the interposer furthest from the bond pad, supports the solder ball, and is sufficiently wide to support the solder ball without allowing the solder ball to come in contact with the traces. The solder ball and the trace routing on the lower surface of the substrate is in different planes, thereby allowing a simplified trace routing, but retaining and even increasing rigidity of the structure and coplanarity of the solder balls.

Interposer for ball grid array (BGA) package

An integrated circuit package, and integrated circuit assembly having such a package, includes a base portion and a cover portion which cooperatively enclose an integrated circuit chip. The base and cover portions are formed of composite material and have matching coefficients of thermal expansion. Because the base and cover portions each match the other's thermal expansions and contractions, no stresses are generated in the package from heating and cooling during and following operation of the integrated circuit chip, and no such thermally produced physical stresses are transferred to the circuit chip to shorten its life. A version of the package includes plural lamina, and may include facial metallic coating layers on the lamina for shielding, electromagnetic shielding, and electrical interconnection of the integrated circuit chip. Another version of the package utilizes the facial metallic coating layers to join portions of the package by soldering.

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Pleasanton, CA, United States of America

Karla Y Carichner