International Business Machines Corporation

Nathalie Normand

Kang-Wook Lee

Valerie A Oberson

Jae-Woong Nah

Jeffrey P Gambino

Timothy Harrison Daubenspeck

Wolfgang Sauter

Timothy Dooling Sullivan

Christopher David Muzzy

David L Questad

The present invention is directed to flux compositions and uses thereof. One composition comprises an activator and a solvent being a glycerol ethoxylate with a molecular weight of 200-500. Another composition comprises an activator, a solvent being a glycerol ethoxylate with a molecular weight of 200-500 and an amine. A soldering method for joining objects is also provided, comprising the steps of applying a flux composition to at least a portion of one or more of the objects, and joining the objects.

Flux composition and techniques for use thereof

The present invention is directed to a soldering method for joining objects is also provided, comprising the steps of applying a flux composition to at least a portion of one or more of the objects, and joining the objects.

The present invention is directed to flux compositions. One composition comprises an activator, a medium-viscosity solvent being a polymer, and a high-viscosity solvent being a copolymer containing first monomers and second monomers. Another composition comprises an activator, and a high-viscosity solvent comprising a copolymer containing first monomers and second monomers. Another composition comprises an activator of 6-12 percent by weight of glutaric acid, pimelic acid, tartaric acid, or mixtures thereof, and a medium-viscosity solvent of 88-94 percent by weight comprising a polymer with hydroxyl end groups. Another composition comprises an activator in a liquid state comprising poly(ethylene glycol)-diacid, and a medium-viscosity solvent comprising a polymer with hydroxyl end groups.

Structures and methods for forming good electrical connections between an integrated circuit (IC) chip and a chip carrier of a flip chip package include forming one of: a tensile layer on a front side of the IC chip, which faces a tops surface of the chip carrier, and a compressive layer on the backside of the IC chip. Addition of one of: a tensile layer to the front side of the IC chip and a compressive layer the backside of the IC chip, may reduce or modulate warpage of the IC chip and enhance wetting of opposing solder surfaces of solder bumps on the IC chip and solder formed on flip chip (FC) attaches of a chip carrier during making of the flip chip package.

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Bromont, Canada

Nathalie Normand