International Business Machines Corporation

Raj N Master

Lester W Herron

Raymond A Jackson

William Edward Sablinski

David C Linnell

Robert W Nufer

Kathleen Ann Lidestri

Paul H Palmateer

Thomas Anthony Wassick

Sudipta Kumar Ray

Mario John Interrante

Srinivasa S Reddy

Philip L Flaitz

Rao R Tummala

Joseph M Harvilchuck

Edward F Handford

Sampath Purushothaman

Jon Alfred Casey

Chandrasekhar Narayan

Sarah Huffsmith Knickerbocker

Paul A Totta

Ananda H Kumar

Steven M Kandetzke

John Acocella

Renuka S Divakaruni

Herbert R Anderson, Jr

Norman G Ainslie

Daniel P Kirby

Derry J Dubetsky

Marvin S Pittler

Joseph M Dynys

Deformation of a lifting ring of bimetallic structure or memory metal is matched to a solder softening or melting temperature to apply forces to lift a chip from a supporting structure, such as a substrate or multi-chip module, only when the solder connections between the chip and the supporting structure are softened or melted. The temperature of the chip, module and solder connections there between is achieved in a commercially available box oven or belt furnace or the like and results in much reduced internal chip temperatures and thermal gradients within the chip as compared to known hot chip removal processes. Tensile and/or shear forces at solder connections and chip and substrate contacts are much reduced in comparison with known cold chip removal processes. Accordingly, the process is repeatable at will without significant damage to or alteration of electrical characteristics of the chip or substrate.

In-situ device removal for multi-chip modules

A cost efficient, highly reliable method to remove electronic devices and components from substrates eliminates separate tooling for every substrate and device or component size. The apparatus which implements the method allows for multiple device or component removal simultaneously, or in a single sequential operation, in a nondestructive action in a very low cost environment. A box oven and vacuum system and is used with different device or component and substrate sizes providing a simple, low cost, molten device removal procedure, eliminating the need for thermal monitor build and associated profiling for each product. The apparatus works independently of chip type or size, utilizing universal fixturing, and can be set up to pull multiple devices and/or components in a single run.

Hot vacuum device removal process and apparatus

The present invention relates generally to a new method of repairing electrical lines, and more particularly to repairing electrical lines having an opening at the module level with devices in place. Various methods and processes are used to repair this open or defective portion in an electrical conductor line. It could be repaired by securing a jumper wire or nugget across the open or the repair could be made by a deposition process, which includes but is not limited to filling the opening with a solder type material or inserting a solder coated electrical wire and heating the solder and allowing the solder to melt and repair the open. One of the attributes of this invention is the ability to repair on a substrate or module on which active components such as chips, and passive components such as pins, capacitors, etc. have been attached. The invention also allows repair of fine line patterns which are normally not repairable by conventional techniques.

Structure for repairing electrical lines

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

The present invention relates generally to a new method of repairing electrical lines, and more praticularly to repairing electrical lines having an open at the module level with devices in place. Various methods and processes are used to repair this open or defective portion in an electrical conductor line. It could be repaired by securing a jumper wire or nugget across the open or the repair could be made by a deposition process, which includes but is not limited to filling the open with a solder type material or inserting a solder coated electrical wire and heating the solder and allowing the solder to melt and repair the open. One of the attributes of this invention is the ability to repair on a substrate or module on which active components such as chips, and passive components such as pins, capacitors, etc. have been attached. The invention also allows repair of fine line patterns which are normally not repairable by conventional techniques.

Method and structure for repairing electrical lines

The present invention provides a method for producing multilayered ceramic structures having copper-based conductors therein, wherein the onset of sintering of the copper-based conductor can be adjusted to approach or match that of the ceramic portion of the structure. In addition, methods are provided whereby the polymeric binder resin used in formation of the ceramic portion of the structure can be removed or burned-off, using oxygen-containing ambients, wherein the oxygen content is greater than 200 ppm, without oxidation of the copper-based conductors therein.

Method of making multilayered ceramic structures having an internal

In the process of braze attachment of electronic package members, such as attaching metallic coated connector pins to a multilayer ceramic substrate, contact areas of the substrate are formed by sequential coatings of molybdenum and nickel, which are heated to diffuse the nickel. A pure gold paste is applied by screen printing, for example, followed by the step of firing to burn out the paste binder and to sinter the pure gold particles onto a dense low porosity structure. The sintering operation converts the Ni film into a continuous Au-Ni solid solution. During pin braze, Ni-Sn intermetallics are dispersed in a gold rich matrix of the Au-Ni solid solution.

Process for braze attachment of electronic package members

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

The bonding of nickel, cobalt, copper or any number of metals to oxide ceramics is achieved whereby the substrate and associated metallurgy are co-sintered. The invention teaches the use of an intermediary oxide such as Al2O3, Cr2O3, TiO2 or ZrO2 which will adhere to the substrate and in the presence of firing ambients form a complex ternary oxide with the overlying metal thereby creating the desired bond. The eutectic can be created during the firing cycle without the undesired consequence of oxidizing the metal. The so-called intermediary oxides can be oxidized in situ, deposited as oxides, or introduced into either the ceramic composition or the metal paste.

Bonding of pure metal films to ceramics

A process for removing organic materials from an article formed from a slurry of glass and/or ceramic particles, resin binder, and a solvent for the resin binder, the process involving including in the slurry a particulate catalyst selected from the group consisting of Cu, Cu.sub.2 O, CuO, Cu.sub.2 SO.sub.4, CuCl.sub.2, Cu organometallic compounds, and mixtures thereof, the catalyst promoting a rapid and complete removal from the shaped article when heated of the organic materials of the slurry.

Method for removal of carbonaceous residues from ceramic structures

A method for fabricating a molecular matrix print head for use in nonimpact electrolytic printers. Green ceramic sheets are stacked and laminated, then embossed with insulators and screened with ruthenium dioxide. The assembly is then co-sintered at less than 1000.degree. C. and the resulting structure smoothed by lapping and finished in a convention fashion.

Material and process set for fabrication of molecular matrix print head

The obtention of enhanced planarity and dimensional integrity of sintered glass-ceramic substrates containing multi-level distribution of conductor patterns (e.g. copper) by a two stage firing of the green sheets, first between the anneal and softening points of crystallizable glass particles, interrupting the firing, superimposing selected light weights on the substrates, and heating through the coalescing temperatures to the crystallization of the glass.

Process for flattening glass-ceramic substrates

The formation of sintered glass-ceramic substrates containing multi-level, interconnected thick-film circuit patterns of copper-based conductors obtained by firing in a controlled ambient of hydrogen and H.sub.2 O at temperatures below the melting point of copper.

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Wappingers Falls, NY, United States of America

Raj N Master