International Business Machines Corporation

Michael A Cohn

Robert J Sullivan

Jon Alfred Casey

Ryan Wayne Wuthrich

Candace A Sullivan

Christopher N Collins

Joseph P DeGeorge

Andrew H Vogel

Robert Anthony Rita

Rao Venkateswara Vallabhaneni

Michael E Cropp

Kurt Elmer Bastian

Italo A DiNunzio

Benjamin V Fasano

Raschid Jose Bezama

Gregory M Johnson

John Joseph Garant

Alan Piciacchio

Abubaker S Shagan

Teresa L Pinto

Nancy A Wier-Cavalieri

Robert C Greenlese

Leslie J Wiands

Adrienne M Tirch

James J Burte

A method of and novel composition for transient liquid phase bonding of refractory metal structures is described herein. Preferably, the composition comprises a first component substantially similar to the composition of the refractory metal structure, and a second component having a lower melting temperature than the first component comprising a metallic constituent selected from the group consisting of iron, nickel and cobalt. The second component acts as a melting point depressant to temporarily lower the melting point of the first component so that the join can be accomplished without melting the structure itself. Upon applying the composition to the surfaces of refractory metal structures in need of joining, the assembly is heated to a eutectic point defined as the lowest melting point of the composition. A localized liquid region is formed at the interface of the two structures which solidifies when the second component diffuses into the structures such that the region becomes increasingly refractory thereby solidifying into a substantially refractory joint.

High temperature refractory joining paste

An interface layer for separating first and second microelectronic ceramic substrates during firing includes a thermally degradable binder, preferably a polymer, that degrades at temperatures above room temperature and below a firing temperature for the microelectronic ceramic substrates, and a separating material, such as boron nitride or graphite. The method of making the interface layer includes mixing the binder, one or more solvents for the binder, a plasticizer and the separating material for a sufficient period of time to form a homogeneous mass, then casting the material in a thin sheet to form the interface layer.

Method of making an interface layer for stacked lamination sizing and sintering

Metal pastes used in the fabrication of multilayer ceramic (MLC) substrates used in semiconductor devices. The pastes reduce substrate defects, such as via bulge and camber. The pastes are comprised of a metal having high conductivity, frit which includes glass, an organic binder, and a solvent, optionally with a surfactant.

Pastes for improved substrate dimensional control

Greensheets having enhanced flexibility and strength are prepared from a greensheet casting composition comprising alumina or other ceramic having a mean particle size of less than about 1 micron and being substantially unimodal, a binder resin, a solvent system and a plasticizer. The greensheets may be formed having a thickness of about 50 microns using conventional greensheet fabricating devices. The greensheets are particularly suitable as dielectric layers for internal layer capacitors in a multilayer ceramic substrate. A preferred co-sintering heating profile to avoid blistering of the MLC package is also provided to form the capacitor containing MLC.

Process for fabricating a multilayer ceramic substrate from thin

Camber of ceramic substrates is prevented by placing a conformable load tile over substrates during sintering. The conformable load tile has an initial curvature that facilitates escape of substrate binder gases during a burn out cycle. Subsequently, the conformable load tile conforms to the substrates under the higher heat of sintering temperature to maintain flatness of the substrates. To prevent sticking of the conformable load tile to the substrates, the conformable load tile is provided with a nonstick surface.

Weighted sintering process and conformable load tile

A process for making multiple microelectronic ceramic substrates uses an interface layer between stacked layers of green sheets that are laminated with the interface layer, then fired to produce the ceramic substrates. The interface layer acts to protect the substrates, and to hold them together before firing, then thermally degrades at a desired point in the firing cycle to separate the individual substrates. The invention also includes the ceramic substrates produced by the method.

Method of using an interface layer for stacked lamination sizing and

Method of making an interface layer for stacked lamination sizing and

A stacking system includes a frame having recesses therein used to partially define openings that permit gas generated during firing of a substrate within the space defined by the frame to escape without adversely affecting the substrate. A relatively thin tile placed on the frame provides the system with an additional level for substrates.

Stacking system for substrates

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Ramsey, NJ, United States of America

Michael A Cohn