International Business Machines Corporation

Robert W Nufer

Lester W Herron

John Acocella

John Ulrich Knickerbocker

Jon Alfred Casey

Charles Hampton Perry

James N Humenik

Renuka S Divakaruni

Arnold I Baise

Daniel P Kirby

Sarah Huffsmith Knickerbocker

Srinivasa S Reddy

Ananda H Kumar

Mark A Takacs

Raj N Master

Steven M Kandetzke

Srinivasa N Reddy

Richard A Bates

Leslie C Anderson

Anthony Mastreani

Lovell B Wiggins

David R Clarke

Salvatore J Scilla

Stephen A Milkovich

Allen J Dam

Ray M Bryant

Frank G Pugliese

Amy T Matts

Werner E Dunkel

Lawrence D David

Ajay Prabhakar Giri

Robert O Lussow

George Czornyj

Peter A Agostino

Bernard Schwartz

Liang-Choo Hsia

Cynthia N Felisberto

Krishna Gandhi Sachdev

Harbans S Sachdev

Philip L Flaitz

Constance J Araps

Joseph M Harvilchuck

Herbert R Anderson, Jr

Darbha Suryanarayana

Steven P Young

Arlyne M Flanagan

Gerald F Hait

Stoyan M Zalar

Ceramic green sheets of controlled microporosity and method of making same have been provided. Controlled microporosity is achieved by including certain ionic species in the ceramic composition, particularly boron, phosphorus and copper oxide.

Green sheets of controlled microporosity and method of producing same

A sintered structure is formed from a powdered material by the steps of providing a first, green powdered material which can be a ceramic or metallic ceramic material. A second, preformed mold blank material to the green powdered material, wherein the preformed mold blank will not fuse with the first, green powdered material. The mold blank material is different green material having a higher sintering temperature than the first green powdered material. Then the structure is fired at the sintering temperature of the first, green powdered material; and the preformed mold blank material from the fired powdered material is removed. Grooves can be formed by pressing non-sinterable lines into a green sheet prior to firing. A wave guide unit can be formed in the ceramic. A ceramic structure can be formed with fracture markings in the green powdered material. A heat sink can be composed of sintered metallic ceramic material in the form of a spiral, while the sintered metallic ceramic material of the heat sink can ban composed of laminated layers. The heat sink can include hollow spaces formed from laminated layers. The heat sink can be in the form of a bellows formed from laminated layers of metallic ceramic material.

Non-sintering controlled pattern formation

An in situ stabilizing tool provides a stress relieved, ceramic green sheet for green sheet screened stability. A green sheet stablilization system uses air bearings as a means of conveying a continuous ceramic green sheet web in a frictionless and stress free state. Solvent vapor stabilization of green sheets in a continuous mode adjusts solvent concentration in the air bearing using a solvent bubbler. Solvent vapor is generated from a group of solvents (e.g. hydrocarbons, water, etc.) that can be vaporized and used to solvent plasticize the ceramic green sheets to achieve stress relaxation. Take up loops and sensors adjust for longitudinal shrinkage during the green sheet relaxation process.

Continuous air bearing vapor stabilization system and method

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

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.

A method for co-sintering ceramic/metal multi-layered ceramic substrates wherein X-Y shrinkage is controlled and X-Y distortion and Z-direction chamber are substantially eliminated. Binder-burnoff is substantially not aggravated during this process as well. The process is accomplished by applying selective forces to the surfaces of the ceramic substrates to control lateral movement while allowing Z direction shrinkage movement. Frictional force means, pneumatic forced means and weights are among the means used to supply forces. Cerium oxide is used in certain embodiments to enhance binder-burnoff.

Method and means for co-sintering ceramic/metal MLC substrates

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

In a maskless metal cladding process for plating an existing metallurgical pattern, a protective layer is utilized to isolate those areas of underlying metallurgy on which additional metal plating is not desired. The layer acts as an isolation barrier to protect the underlying metallurgy from deposition and subsequent diffusion of the heavy metal overlay. The composition of the protective layer is selected as one having sufficient mechanical integrity to withstand process handling and support the gold overlay and having the thermal integrity to withstand the high temperatures reached during metal sputtering and diffusion processes. The isolation barrier layer has an organic component as a binder which thermally decomposes, either in a heating step before metal deposition or during the diffusion cycle, leaving no carbonaceous residue but leaving an inert, inorganic standoff to support the metal. After diffusion of the metal, the remaining inorganic standoff layer, overlying metal and any undiffused metal remaining on the non-patterned substrate is easily removed by a standard technique, such as ultrasonics.

Diffusion isolation layer for maskless cladding process

Sintering of metal particles at their normal sintering temperature is inhibited by coating the metal particles with an organic material such as polyvinyl butyral, polyvinyl formvar, polyvinyl alcohol, polyacrylonitrile epoxies, urethanes and cross-linked polyvinyl butyral. The organic coating serves as a barrier preventing physical contact between metal particles during the initial phase of the sintering cycle and degrades into a carbonaceous coating followed by volatilization during the intermediate phase of the cycle permitting coalescence of the metal particles into a dense mass along with the coalescence of the glass-ceramic particles. Co-sintering of the metal particles and the glass-ceramic particles with the aid of the organic coating results in a hermetic multi-layer glass ceramic substrate free of dimensional stability problems without deleteriously affecting the electrical conductivity of the metal conductor pattern.

Method of controlling the sintering of metal particles

In a process for forming elements from a slurry that includes particulate ceramic and/or glass, an organic binder resin, and a solvent for the resin, where the element is shaped from the slurry, and the element heated to remove the organic materials of the slurry and subsequently fuse the ceramic and/or glass particles, the improvement comprised of coating the ceramic and/or glass particles prior to forming the slurry with a surface modification compound selected from the group consisting of organo silanes, organo silazanes, titanium chelates, titanium esters, and mixtures thereof.

Method of bonding inorganic particulate material

Process for forming multilayered ceramic substrate having solid metal

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Robert W Nufer