International Business Machines Corporation

Raymond A Jackson

Sudipta Kumar Ray

Peter Jeffrey Brofman

William Edward Sablinski

Kathleen Ann Stalter

Mario John Interrante

Mark G Courtney

Lewis Sigmund Goldmann

David C Linnell

Hilton T Toy

Shaji Farooq

Patrick Anthony Coico

Gregory Blair Martin

Raj N Master

Kathleen Ann Lidestri

Mukta S Farooq

Stephen Anthony DeLaurentis

John Ulrich Knickerbocker

Frank Louis Pompeo

Li Ming Wang

Amy B Ostrander

Mukta G Farooq

Thomas Anthony Wassick

Charles Hampton Perry

Karl J Puttlitz, Sr

Michael Berger

Joseph M Harvilchuck

Balaram Ghosal

James J Petrone

Mary Ann Emmett

Edward F Handford

Roger A Stinemire

Richard L Chartrand

Richard F Shortt

James M Levite

Krishna Gandhi Sachdev

Sarah Huffsmith Knickerbocker

Thomas Edward Lombardi

Anson Jay Call

Brenda Lee Peterson

James H Covell

Paul A Zucco

Scott R Dwyer

Megan J Shannon

Scott A Bradley

A method and apparatus are provided for reworking electronic component assemblies where the components are joined by solder interconnections. A cutting device employing a heated wire, blade or other cutting element is forced against and through the solder interconnections to sever the interconnections. A preferred cutting device employs moving the cutting element transverse to the solder interconnections to also provide a sawing action to the solder interconnections. Another cutting device employs a water jet to provide a high pressure stream of water that cuts and severs the solder interconnections.

Rework methods for lead BGA/CGA

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 method of joining first and second substrates through a solder element interconnect, the method including the steps of forming solder elements, such as solder balls, in a first array on a first substrate, forming pads of solder paste in a second array on a second substrate wherein the first and second arrays are mirror images of one another, establishing a standoff element on one of the first or second substrates, assembling the first and second substrates such that each of the solder elements on the first substrate are embedded in each of the solder paste pads and the standoff element is interposed between the first and second substrates, heating the first and second substrates at a preferred temperature to cause melting of the solder elements and the solder pads into single solder elements, wherein the standoff controls the separation distance between the first and second substrates.

Single-melt enhanced reliability solder element interconnect

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 for removing at least one molten or solid structure from a surface including: placing the surface with the at least one molten or solid structure in a fixture; disposing said wiper assembly acted on by a bias proximate the at least one molten or solid structure; retaining the wiper assembly in a first position with a device having a first temperature point level equivalent to or higher than a second melting point level of the at least one molten or solid structure; and raising the temperature of the fixture to the first temperature point level; wherein the at least one molten or solid structure is wiped from the surface when the device reaches the first temperature point level. An apparatus for removing at least one molten or solid structure from a substrate for rework, the apparatus comprising: a fixture for sustaining and biasing the substrate against a wiper assembly; the wiper assembly configured and positioned to slidably engage at least a portion of the substrate; a bias for translating the wiper assembly along a surface of the substrate having the at least one molten or solid structure to be removed; and a guide block assembly capable of guiding and locking the wiper assembly.

Apparatus and method for removing interconnections

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

A process and apparatus for removing flip chips with C4 joints mounted on a multi-chip module by applying a tensile force to one or more removal member bonded to the back of one or more flip chips during heating of the module to a temperature sufficient to cause the C4 joints to become molten. The tensile force can either be a compressed spring, or a bi-metallic member which is flat at room temperature and becomes curved when heated to such temperature, or a memory alloy whose original shape is curved and which is bent flat at room temperature but returns to its original curved shape when heated to such temperature. An adhesive is used to bond the removal member to the chip to be removed and is a low temperature, fast curing adhesive with high temperature tolerance after curing.

Process and apparatus to remove closely spaced chips on a multi-chip module

The present invention relates generally to a new structure and method for chip burn-in and/or testing. More particularly, the invention encompasses a baseplate that is secured to a delicate chip and a method for such an invention is also disclosed. The inventive baseplate provides an added strength to a complex chip while it is being tested and/or burned-in, and then during normal use the baseplate of this invention is an integrated component of the chip.

Baseplate for chip burn-in and/of testing, and method thereof

The present invention relates generally to an electrical interconnection package and a method thereof. More particularly, the invention encompasses an invention that increases the fatigue life of a Ball Grid Array (BGA) electrical interconnection. This invention structurally couples at least one module to an organic interposer using a high modulus underfill material. The organic interposer is then joined to a organic board using standard joining processes. The inventive module can then be removed from the organic board at any time by moving the organic interposer using standard rework techniques.

Electrical interconnection package and method thereof

This invention relates to a solder structure which provides enhanced fatigue life properties when used to bond substrates particularly at the second level such as BGA and CGA interconnections. The solder structure is preferably a sphere or column and has a metal layer wettable by solder and the structure is used to make solder connections in electronic components such as joining an electronic module such as a chip connected to a MLC which module is connected to a circuit board. The solder structure preferably has an overcoat of solder on the metal layer to provide a passivation coating to the metal layer to keep it clean from oxidation and corrosion and also provide a wettable surface for attachment of the solder structure to solder on the pads of the substrate being bonded.

Method for enhancing fatigue life of ball grid arrays

A solder preform is provided for forming interconnections between multilayer ceramic substrates comprising an upper layer and lower layer of solder separated by an intermediate layer of a material which is wettable by solder and which does not melt at the temperatures used to reflow the solder and form the connections. The solder preform is used to join the substrates and is particularly useful to simultaneously electrically interconnect the substrates and to form a hermetic seal between the substrates being joined.

Solder disc connection

A ceramic column grid array package suitable for mounting application specific integrated circuits or microprocessor chips onto a printed circuit board employing polymer reinforced columns on the substrate module is described. The polymer enhancement is formed by coating a thin conformal film of a polymer, such as, a polyimide onto the substrate module after the formation of the ceramic column grids to mechanically enhance the column to substrate attachment of the column to the substrate prior to mounting on a printed circuit card. Upon curing of the polymer film at a temperature below the melting point of the solder bond attaching the column grid to the substrate, the columns will be mechanically reinforced in their attachment to the substrate. Upon removal of the substrate module from a printed circuit card during rework, the columns of the grid array will remain with the substrate module, leaving no columns on the printed circuit card.

Polymer enhanced column grid array

A device and method for enabling the reworkability of an integrated circuit comprising a wirebond chip having a bottom surface and a carrier substrate having a first surface and a second surface. The first surface and second surface of the carrier substrate are electrically connected through a series of vias. A bonding agent is used to mechanically attach the wirebond chip to the carrier substrate in addition to wirebonds for electrically connecting the wirebond chip to the substrate. The substrate is attached to a multi-chip module (MCM) by ball grid array (BGA) or controlled collapse chip connection (C4) attaching process.

Reworkability method for wirebond chips using high performance capacitor

A process and apparatus for removing flip chips with C4 joints mounted on a multi-chip module by applying a tensile force to one or more removal member bonded to the back of one or more flip chips during heating of the module to a temperature sufficient to cause the C4 joints to become molten. The tensile force can either be a compressed spring, or a bimetallic member which is flat at room temperature and becomes curved when heated to such temperature, or a memory alloy whose original shape is curved and which is bent flat at room temperature but returns to its original curved shape when heated to such temperature. An adhesive is used to bond the removal member to the chip to be removed and is a low temperature, fast curing adhesive with high temperature tolerance after curing.

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Fishkill, NY, United States of America

Raymond A Jackson