Fry's Metals, Inc.

Alpha Metals, Inc.

David B Blumel

Kenneth Burton Gilleo

Alvin F Schneider

Jack Brous

James McLenaghan

John V Tomczak

A method for applying an underfill and edge coating to a flip chip is described. The method includes the steps of adhering a bumped wafer to an expandable carrier substrate, sawing the wafer to form individual chips, stretching the carrier substrate in a bidirectional manner to form channels between each of the individual chips, applying an underfill material to the bumped surfaces of the chips and around the edges of the chips, cutting the underfill material in the channels between the chips and removing the individual, underfill coated chips from the carrier.

Wafer coating method for flip chips

The present invention relates to a process for forming a two-stage bump on a flip chip. The process employs an underfill material which can be formed to act as a mask for application of bumps formed from a first composition to the flip chip. A material having a different composition can then be applied to the bumps.

Flip chip having integral mask and underfill providing two-stage bump formation

A flip chip having solder bumps, an integrated underfill, and a separate flux coating, as well as methods for making such a device, is described. The device is characterized in that the underfill material is provided on the chip surface prior to the application of solder bumps, and then treated to form apertures therein which act as a mask for solder bump application. The resulting device is well suited for a simple one-step application to a printed circuit board, thereby simplifying flip chip manufacturing processes which heretofore have required a separate underfilling step.

Flip chip with integrated mask and underfill

A flip chip having solder bumps and an integrated flux and underfill, as well as methods for making such a device, is described. The resulting device is well suited for a simple one-step application to a printed circuit board, thereby simplifying flip chip manufacturing processes which heretofore have required separate fluxing and underfilling steps.

Flip chip with integrated flux and underfill

A rosin-free, low VOC, no-clean soldering flux consists essentially of one or more halide-free carboxylic acid activators in an aggregate amount not exceeding about 8% by weight of the flux; one or more alkyl amines capable of forming amine salt of the one or more activators and in an aggregate amount not exceeding about 10% by weight of the flux; and water, with or without a surfactant. The flux is particularly useful in a method of producing soldered printed wiring assemblies with minimal residual ionic contamination, so that post-soldering cleaning of the assemblies is unnecessary.

Rosin-free, low VOC, no-clean soldering flux and method using the same

A no-clean soldering flux consists essentially of one or more halide-free, water soluble activators in an aggregate amount not exceeding about 5% by weight of the flux, a water soluble fluorinated surfactant in an amount not exceeding about 1% by weight of the flux, and water. The flux is substantially VOC-free and is particularly useful in a method of producing soldered printed wiring assemblies with minimal residual ionic contamination, so that post-soldering cleaning of the assemblies is unnecessary. The absence of significant amounts of VOC's and the elimination of post-soldering cleaning result in substantial environmental and production-related benefits.

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New York, NY, United States of America

David B Blumel