International Business Machines Corporation

Amy B Ostrander

Raymond A Jackson

Charles Hampton Perry

John Ulrich Knickerbocker

Krishna Gandhi Sachdev

Mario John Interrante

Thomas Edward Lombardi

Lewis Sigmund Goldmann

Brenda Lee Peterson

Megan J Shannon

The invention is directed to improved conductive adhesives for solder-free interconnections in microelectronic assembly processes such as for chip carrier-to-substrate attachment. These adhesives are characterized by low tensile modulus, low resistivity, high adhesion strength, and durability of these properties during reliability stress conditions of thermal shock, thermal aging, and temperature/humidity (85&deg; C./85%) exposure of the assembled devices. The adhesives contain a homogeneous solution of a siloxane containing epoxide, a curing agent, a curing catalyst and an organic polymeric or oligomeric additive. A conductive filler is added to the solution forming the filler. Preferred fillers are Ag coated with Pd and Ag coated with Au.

Epoxy-siloxanes based electrically conductive adhesives for semiconductor assembly and process for use thereof

A structure and method for converting a standard ceramic carrier into a temporary chip attach carrier, wherein the device comprises a substrate, a plurality of metal vias interspersed in the substrate, a carrier layer further comprising a cavity dam with a plurality of holes filled with conductive adhesive. The process of forming the temporary chip attach carrier comprises applying a secondary layer further comprising a plurality of holes on a substrate, applying conductive adhesive in the holes, curing the adhesive, placing a chip containing C4 solder bumps onto the secondary layer, applying a force onto the chip, testing and burning-in the secondary layer, removing the force from the chip, separating the chip from the secondary layer, and then re-using the secondary layer.

Use of conductive adhesive to form temporary electrical connections for use in TCA (temporary chip attach) applications

A method and apparatus is provided for forming an electronic assembly whereby an insulating polymer matrix having a plurality of conductor holes is attached to a first substrate wherein the conductor holes align with a corresponding contact array on the first substrate. Subsequently, a flexible, electrically conductive adhesive is provided within the plurality of conductor holes and a solid conductive material, preferably having a high melting temperature, is attached to at least one end thereof. The insulating polymer matrix with the electrically conductive adhesive and the solid conductive material is then cured at a temperature sufficient to completely cure the matrix to completely surround the electrically conductive adhesive, as well as permanently attaching the matrix and conductive adhesive to the first substrate and permanently attaching the solid conductive material to the conductive adhesive. A second substrate may then be attached to the conductive matrix structure secured to the first substrate by providing a low melting temperature attachment means to the solid conductive material attached to the matrix and subsequently reflowing the assembly to form an electronic assembly adapted with the capability of reworkability.

Conductive adhesive interconnection with insulating polymer carrier

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Wappingers Falls, NY, United States of America

Amy B Ostrander