International Business Machines Corporation

Guy D Beaumont

Alain Warren

Denis Labbe

Peter Alfred Gruber

David Hirsch Danovitch

Guy Paul Brouillette

Germain L Caron

Francois P Robillard

The present invention relates to an improved leadframe and method of attaching leads of a leadframe to contact pads on a carrier. The leadframe includes resilient engaging means or fingers for engaging the carrier and for exerting forces on the carrier to thereby support the carrier and accurately position and align the contact pads on the carrier with the leads. This invention overcomes the expense and inaccuracies of known leadframe designs and techniques in attaching leads to carrier contact pads using such things as fixtures for positioning the leadframe and carrier, visual alignment procedures and retaining tabs.

Self align leadframe having resilient carrier positioning means

The described invention provides a method and apparatus for coating uniform films on substrates and curing the coatings on the surface. Within an enclosed chamber the object to be coated is positioned and a sufficient amount of liquid material is provided into the chamber to cover the surface of the object to be coated. The excess liquid material is then evacuated from the chamber at a controlled rate to leave a coating of material on the surface of the object.

Closed chamber method and apparatus for the coating of liquid films

An apparatus and a method for transferring solder bumps from a solder mold to a solder-receiving substrate are disclosed. The apparatus includes a transfer fixture constructed by a base member, a lid member and a compressible member for holding a mold/substrate assembly therein. A plurality of compression pins are mounted through the lid member for supplying a uniform pressure on the mold/substrate assembly and for allowing lateral motion of the mold/substrate assembly relative to the transfer fixture due to a mismatch in the coefficients of thermal expansion. The compressible member is a cellulosic foam sheet which applies a uniform joining force across the entire surface of a wafer and assures abutting contact between the entire wafer and the mold surface. The foam sheet further assists in the lateral movement of the mold/substrate assembly relative to the base member of the transfer fixture.

Apparatus for transferring solder bumps and method of using

Leadframe having resilient carrier positioning means

A method is provided for creating solder connections between two surfaces which connections are relatively weak and thus can be readily fractured for separating the surfaces. The preferred application of the disclosed process is its use in connecting semiconductor chips to a carrier in order to conduct burn-in tests on the chips. The process consists of a series of steps to form a surface having a matrix of solder wettable and solder non-wettable areas on the pads of the carrier. Once the solder balls on the chip are attached to the treated pads on the carrier, electrical contacts are made and the chip can be readily removed after the test. The uniquely configured carrier can then be reused numerous times for testing or burning-in chips.

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Granby, Canada

Guy D Beaumont