Lucent Technologies Inc.

At+t Corp.

At&t Bell Laboratories

American Telephone and Telegraph, Co.

Fred W Verdi

Mark B Clifton

Richard Michael Flynn

Peter F Lilienthal, Ii

Richard Haynes

Robert B Levy

Albert Holliday

Richard M Flynn

Maureen B Schmidt

Jack P Honore

An EMI shield for use on a printed wiring board (PWB) of a circuit pack includes an open-ended box-like structure having a laterally extending flange completely encircling the opening into the box-like structure. The box is of an EMI impervious material, preferably stainless steel. An electrically conductive O-ring gasket is disposed in a groove in the flange. Both the groove and the flange completely encircle the box opening. The shield is secured to a PWB by pegs secured to the flange at positions radially outwardly of the gasket and extending entirely through openings through the PWB. Preferred pegs comprises pairs of side-by-side prongs integral with the shield flange but extending downwardly therefrom. Each prong terminates in an oppositely directed, return-bent detent with the detent pairs functioning as a spring-biased latch for removably mounting the shield to the PWB.

Circuit board RF shielding

The present invention is directed to an integrated circuit package having improved EMI characteristics. In accordance with one aspect of the invention, a ball grid array integrated circuit package is provided for attachment to a circuit board. The circuit package includes a substrate having a semiconductor die defining an electronic circuit formed thereon. A matrix of spherically-shaped package leads is disposed adjacent the substrate and opposite the semiconductor die. Conductive elements, such as bond wires, electrically connect circuit points on the semiconductor die to the package leads. Further, at least one conductive element electrically interconnects each of the leads that define a perimeter of the matrix of package leads, for electrical connection to ground. In the preferred embodiment, adjacent leads of the perimeter matrix are separated by a spacing that is no greater than 1/20 of the wavelength of the highest frequency electrical signal carried on any of the signal leads. In accordance with another aspect of the invention, a printed circuit board assembly comprises a circuit board substrate having conductive elements and a socket area for receiving a semiconductor package, wherein the socket area is defined by a matrix of conductive pads. Each conductive pad includes a metal coating and is shaped to receive a lead of the semiconductor package. Finally, at least one conductive element or trace electrically connects each of the conductive pads that define a perimeter of the matrix of conductive pads, for electrical connection to ground.

Ball grid array semiconductor package having improved EMI characteristics

Thin semiconductor die, approximately 0.004 to 0.007 inches thick, are positioned substantially on the neutral plane of a smart card, the neutral plane defined as the plane of substantially no mechanical strain during flexure of the smart card, thereby providing smart cards having improved resistance to mechanical flexure, and/or smart cards having improved RF performance.

Smart cards having thin die

Improved methods for fabricating smart cards are disclosed. Semiconductor die approximately 0.004 to 0.007 inches thick are fabricated using chemical stress relief processes and UV dicing tape. The die are positioned substantially on the neutral axis of a smart card, thereby providing smart cards having improved resistance to mechanical flexure.

Method for fabricating thin, strong, and flexible die for smart cards

An improved electrical connection between each of a set of metallized areas (16) on a first substrate (11 ) and those on a second substrate (12), via a layer of anisotropically conductive material (22) sandwiched therebetween, is obtained by arraying the metallized areas in concentric rings about each of a plurality of fasteners (28) extending through both substrates and the material. By arraying the metallized areas in concentric rings about each fastener, the anisotropically conductive material in contact with the metallized areas arrayed in each ring will advantageously be subjected to a uniform pressure by the fastener, improving the conductivity of the material.

Interconnection method and apparatus

A personal data card (10) is fabricated from a polymer thick-film circuit (12) formed of a polymer sheet (14) having a plurality of pads (16 and 17) and interconnecting paths (18) printed thereon with a copper-filled polymer ink. Each of a selected set of the pads (16) has a layer of nickel (22) applied to it, and then a layer of gold (24) applied above the nickel, to facilitate wire bonding of each of a plurality of aluminum leads (21), associated with a semiconductor die (19), to a corresponding pad. Use of such a polymer thick-film circuit (12) in the fabrication of the data card (10) reduces the cost of the card.

Personal data card fabricated from a polymer thick-film circuit

An electronic game (10) is provided with at least one, and preferably a plurality, of intelligent game pieces (14,14' ) which each contain a re-programamble memory device (30,70). The memory device (30,70) in each of the game pieces (14 and 14', respectively), stores characteristics of an activity to be simulated by the game (10). By re-programming the game pieces (14,14'), the characteristics of the activity simulated by the game (10) can be changed to make the activity more interesting and challenging.

Electronic game having intelligent game pieces

A personal data card (10), comprised of a semiconductor chip (28), sealed by encapsulant (38) in an opening (26) in a body (12), is advantageously provided with a shock absorbing device (38) which substantially circumscribes the encapsulant to substantially isolate the encapsulant from the body of the card. By isolating the encapsulant from the card body, the shock absorbing device reduces the stresses transmitted from the card body into the capsulant and into the chip when the card is flexed. In this way the incidence of cracking of the chip caused by the stresses generated upon flexing of the card is reduced.

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Lawrenceville, NJ, United States of America

Fred W Verdi