Xilinx, Inc.

Steven H C Hsieh

Siuki Chan

Paul Ying-Fung Wu

Soon-Shin Chee

A lid having a plurality of recesses at the edges of the lid to provide an improved adhesive bond between the lid and a substrate of an integrated circuit is disclosed. The plurality of recesses may be a castellation comprising a collection of semi-circular cuts into the originally straight edges of the lid. The castellation can be formed by stamping, etching, molding design, or milling/drilling, all of which are well-known methods in the art of forming lids for integrated circuits. The castellation can be vertically straight or it can be slightly tapered, to provide a better locking of the lid on to the package. Epoxy in the recesses can provide an epoxy post for locking the lid. Method of forming a lid having a plurality of recesses and employing a lid on an integrated circuit are also disclosed.

Lid and method of employing a lid on an integrated circuit

Disclosed is a DC thermal energy generator for heating localized regions of an integrated circuit. The integrated circuit includes a pair of static circuits whose outputs are shorted, and are in contention. Contention causes current to flow through the circuits, generating heat. Integrated-circuit temperature can be varied by turning on more or fewer thermal energy generators. The thermal resistance of a packaged integrated circuit is computed using a well-known relationship among the integrated circuit's measured temperature, power consumption, and the ambient temperature.

Methods and circuits for measuring the thermal resistance of a packaged IC

Test methods and circuits isolate thermal effects from AC effects on circuit performance. Critical paths for a failing programmable logic device (PLD) are identified and tested. This testing minimizes the impact of power-supply flicker and noise by eliminating or inactivating circuitry not required to test the critical paths. DC thermal energy generators are instantiated on the PLD adjacent the critical paths to heat the critical paths to one or more test temperatures. The critical paths are then tested over an appropriate range of temperatures and supply-voltages.

Methods and apparatus for isolating critical paths on an IC device having a thermal energy generator

Disclosed is a DC thermal energy generator for heating localized regions of an integrated circuit. The integrated circuit includes a pair of static circuits whose outputs are shorted, and are in contention. Contention causes current to flow through the circuits, generating heat. Integrated-circuit temperatures can be varied by turning on more or fewer thermals energy generators. The thermal resistance of a, packaged integrated circuit is computed using a well-known relationship integrated circuit's measured temperature, power consumption, and the ambient temperature.

A method and assembly for testing multiple IC packages for solder joint fractures that occur in response to thermal cycling. A test PCB is fabricated with contact pads arranged to match a BGA IC package footprint, wherein pairs of the contact pads are linked by conductive traces (lines) to form a lower portion of a daisy chain. The BGA IC package is modified to link associated pairs of solder balls, e.g., using wire bonding to form an upper portion of the daisy chain. Mounting the BGA IC package on the test PCB completes the daisy chain. By alternating between the test PCB contact pads that are linked by conductive traces and the solder balls that are linked by wire bonding, the daisy chain provides a conductive path that passes through all solder balls of the BGA IC package.

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Cupertino, CA, United States of America

Steven H C Hsieh