International Business Machines Corporation

John Acocella

Robert W Nufer

Lester W Herron

Sarah Huffsmith Knickerbocker

Srinivasa S Reddy

John Ulrich Knickerbocker

Jon Alfred Casey

John Saunders Corbin, Jr

James N Humenik

Lawrence D David

Mark A Takacs

Steven M Kandetzke

Karl G Hoebener

Renuka S Divakaruni

Joseph Angelo Benenati

Richard A Bates

Arnold I Baise

Donald R Banks

Daniel P Kirby

Lovell B Wiggins

David R Clarke

David P Watson

Thomas Caulfield

Amy T Matts

Charles Hampton Perry

Ajay Prabhakar Giri

Robert O Lussow

George Czornyj

Srinivasa N Reddy

Anthony Mastreani

Peter A Agostino

Louis H Wirtz

Bernard Schwartz

Salvatore J Scilla

Liang-Choo Hsia

Mark R Kordus

Mark S Schneider

Werner E Dunkel

Allen J Dam

Ray M Bryant

Alfred Grill

Sampath Purushothaman

Chandrasekhar Narayan

Vishnubhai Vitthalbhai Patel

Bernard S Meyerson

Gaetano Paolo Messina

Philip L Flaitz

Raj N Master

Egidio E Marotta

Paul H Palmateer

Nanik Bakhru

Steven P Young

Seaho Song

Albert J Fahey

High melting temperature Pb/Sn 95/5 solder balls are connected to copper pads on the bottom of a ceramic chip carrier substrate by low melting temperature eutectic Pb/Sn solder. The connection is made by quick reflow to prevent dissolving Pb into the eutectic solder and raising its melting temperature. Then the module is placed on a fiberglass-epoxy circuit board with the solder balls on eutectic Pb/Sn solder bumps on copper pads of the board. The structure is reflowed to simultaneously melt the solder on both sides of the balls to allow each ball to center between the carrier pad and circuit board pad to form a more symmetric joint. This process results in structure that are more reliable under high temperature cycling. Also, to further improve reliability, the balls are made as large as the I/O spacing allows without bridging beam on balls; the two pads are about the same size with more solder on the smaller pad; the pads are at least 75% of the ball diameter; and the eutectic joints are made as large as possible without bridging between pads. For reliability at even higher temperature cycles or larger substrate sizes columns are used instead of balls.

Solder ball connections and assembly process

Two substrates are produced each with a planar, mirror-image matrix of metal contacts in a surface wiring layer. The substrates are positioned with the matrices in parallel confrontation which defines pairs of confronting contacts. A metal ball is positioned between each pair of contacts with a respective volume of joining material between the ball and each of the two respective contacts. The volumes of joining material are simultaneously melted to allow surface tension to align the substrates and to accurately center the balls between each respective pairs of contacts in a plane defines by the matrix of balls.

Solder ball interconnected assembly

The present invention relates generally to new structures for decals, and more particularly to electrically conductive decals filled with inorganic insulator material. Various methods and processes that are used to make these electrically conductive decals filled with inorganic dielectric material are disclosed.

Structures for electrically conductive decals filled with inorganic

An integrated circuit thermal conduction module comprises a substrate having a chip-carrying surface and at least one integrated circuit chip on the substrate. A deformable, liquid-impermeable, thermally conductive film or foil extends over an upper surface of the chip. A piston has a lower surface which urges and conforms the film against the chip upper surface and which contains at least one open channel permitting coolant passage and contact with the film for conveying heat from the chip without direct contact between the coolant and chip. Preferably, the piston has a central passageway extending along the longitudinal axis for channeling the coolant through the piston, and has a plurality of channels extending radially outwardly from the central passageway along the lower face for directing coolant beneath the piston.

Apparatus for indirect impingement cooling of integrated circuit chips

The cracking experienced during thermal cycling of metal:dielectric semiconductor packages results from a mismatch in thermal co-efficients of expansion. The non-hermeticity associated with such cracking can be addressed by backfilling the permeable cracks with a flexible material. Uniform gaps between the metal and dielectric materials can similarly be filled with flexible materials to provide stress relief, bulk compressibility and strength to the package. Furthermore, a permeable, skeletal dielectric can be fabricated as a fired, multilayer structure having sintered metallurgy and subsequently infused with a flexible, temperature-stable material to provide hermeticity and strength.

Process for fabricating a low dielectric composite substrate

A method of forming an adherent layer of metallurgy on a ceramic substrate which includes the steps of obtaining a ceramic material containing a polymeric binder and copper metallurgy patterns within the ceramic body. In one embodiment of the invention, the ceramic body also contains MgO. Thereafter, a surface layer of metallurgy is formed on the surface of the ceramic body. In one embodiment, the surface layer is nickel and in another embodiment, the surface layer is copper or gold. Then, the ceramic body undergoes a sintering cycle which includes the steps of pyrolysis, binder burnoff and, lastly, densification and, in some cases, crystallization. During densification and crystallization, there is a predetermined steam atmosphere which meets the following requirements: a partial pressure of oxygen less than that necessary to satisfy the equilibrium equation 4Cu+O.sub.2 =2Cu.sub.2 O; and a partial pressure of oxygen less than or equal to that necessary to satisfy the equilibrium equation 2Ni+O.sub.2 =2NiO for nickel in said surface metallurgy.

Method of forming an adherent layer of metallurgy on a ceramic substrate

Low dielectric composite substrate

The cracking experienced during thermal cycling of metal:dielectric semiconductor packages results from a mismatch in thermal co-efficients of expansion. The non-hermeticity associated with such cracking can be addresssed by backfilling the permeable cracks with a flexible material. Uniform gaps between the metal and dielectric materials can similarly be filled with flexible materials to provide stress relief, bulk compressibility and strength to the package. Furthermore, a permeable, skeletal dielectric can be fabricated as a fired, multilayer structure having sintered metallurgy and subsequently infused with a flexible, temperature-stable material to provide hermeticity and strength.

The present invention relates generally to new processes for making decals, and more particularly to electrically conductive decals filled with inorganic insulator material. Various methods and processes that are used to make these electrically conductive decals filled with inorganic dielectric material are disclosed.

Processes for electrically conductive decals filled with inorganic

A device that contains a copper substrate; a rigidizing layer and/or a metal layer, and a non-graphitic hard carbon layer deposited on the rigidizing layer; and use as a heat sink or piston for electronic components.

Copper device and use thereof with semiconductor devices

A multilayered ceramic (MLC) substrate having embedded and exposed conductors suitable for mounting and interconnecting a plurality of electronic devices exterior thereof. The horizontal planar conductors comprise substantially a plurality of solid, non-porous, homogeneous metal patterns, whereas the vertical interplanar connection conductors are substantially porous metal conductors that are formed by methods such as screening. The process to form the MLC substrate involves forming a pattern of solid, nonporous conductors to a backing sheet having a release layer, then transferring the pattern to a ceramic green sheet. Zero X-Y shrinkage sintering processes allow the MLC substrate and solid metal conductors to be densified without distortion of the solid metal patterns or the ceramic.

Multilayered ceramic substrate having solid non-porous metal conductors

Process for forming multilayered ceramic substrate having solid metal

A metal etching process involving an oxidation-reduction reaction where the metal being etched is oxidized and the active ingredient in the etchant solution is reduced, incorporates contacting said metal with an etching solution containing an active ingredient selected from the group consisting of ferric ions, ferricyanide ions, ceric ions, chromate ions, dichromate ions, and iodine, and introducing ozone into said etching solution to rejuvenate and agitate the solution.

Metal etching process with etch rate enhancement

Growing community of inventors

Hopewell Junction, NY, United States of America

John Acocella