International Business Machines Corporation

William J Summa

David W Wang

Konstantinos I Papathomas

Ashit A Mehta

Michael J Canestaro

Patrick Robert Zippetelli

Michael J Cibulsky

Lee P Springer

Jonathan David Reid

Robert Maynard Japp

Kostas I Papathomas

William John Rudik

Gerald Walter Jones

Charles Robert Davis

Richard W Carpenter

Warren A Alpaugh

Frederick R Christie

William H Lawrence

Leroy N Chellis

Peter J Lueck

Robert J Cox

W Robert Pratt

Edward J Bonafino

Tyan M Niu

Lee P Wilding

Eugene A Eggers

John M Brauer

A rigid-flexible circuit board is fabricated by providing a core having a dielectric substrate and conductive layer thereon. A sub-composite comprising a polyimide and rigid dielectric substrate adjacent the conductive layer and in both the rigid and flexible segments of the board is provided. A release layer corresponding to the flexible segment of the board is provided. A rigid bonding layer is provided at rigid segments of the board but not at the flexible segments. A composite is formed by providing a second conductive layer adjacent the rigid bonding layer. The composite is laminated. Portions of the second conductive layer corresponding to the flexible segment and release layer are removed.

Composite for providing a rigid-flexible circuit board construction and

Disclosed are thin film triazine adhesives on organic carriers, method for making them and microelectronic circuit packages incorporating them. The circuit package has a substrate made up of organic, dielectric, polymeric sheets. At least one pair of the polymeric sheets face each other and are adhesively joined together by a triazine polymer.

Triazine thin film adhesives

A composite for providing a rigid-flexible circuit board includes at least one core that contains a dielectric substrate and at least one conductive layer thereon; at least one sub-composite that includes a polyimide and a rigid dielectric substrate; a release layer; at least one rigid bonding layer and a second conductive layer. The composite is used in the fabrication of a rigid-flexible circuit board.

Disclosed are filled poly(triazine) resin dielectrics and microelectronic circuit packages incorporating them. In the filled poly (triazine) dielectric composites, dispersed thermoplastic polymeric fillers are used to reduce the brittleness and increase the ductility of the triazine polymer, while preserving the low dielectric constant of the triazine host matrix-based composite.

Mechanically enhanced, high impact strength triazine resins, and method

Disclosed is a polymeric product of diglycidyl bis phenol p-dialkyl benzene, and dicyanate diphenyl hexafluoro isopropane. Also disclosed is an organic polymeric dielectric composite of organic polymeric films, as polyimide films, dispersed in and reinforcing the organic polymeric adhesive reaction product of diglycidyl bis phenol p-dialkyl benzene, and dicyanate diphenyl hexafluoro isopropane. Further disclosed is an electronic circuit package that is adapted to receive at least one microelectronic circuit chip, with at least one layer having a substrate of an organic polymeric dielectric composite of organic polymeric films and the organic polymeric adhesive reaction product of diglycidyl bis phenol p-dialkyl benzene, and dicyanate diphenyl hexafluoro isopropane.

Adhesives on polymide films and methods of preparing them

Disclosed is a method of fabricating a multilayer electronic circuit package. The multilayer circuit package has at least one layer that is a circuitized, polymer encapsulated metal core. According to the method of the invention a metal foil is provided for the metal core of the layer. This metal core foil may be provided as a single unit or in a continuous, roll to roll, process. The vias and through holes are drilled, etched, or punched through the metal foil. An adhesion promoter is then applied to the perforate metal foil for subsequent adhesion of polymer to the foil. The dielectric polymer is then applied to the perforate metal foil core by vapor depositing, chemical vapor depositing, spraying or electrophoretically depositing, a thermally processable dielectric polymer or precursor thereof onto exposed surfaces of the perforate metal foil including the walls of the through holes and vias. The dielectric polymer or precursor thereof is then thermally processed to form a conformal dielectric, polymeric coating on surfaces of the perforate metal foil, including the interior surfaces of the vias and through holes. This dielectric, polymeric coating may then be circuitized, and coated with an adhesive for lamination to the next adjacent layer. After lamination, one or more chips are attached to the completed package.

Method for fabricating metal core layers for a multi-layer circuit board

A flame retardant, low dielectric constant, controlled coefficient of thermal expansion, low cost prepreg material which includes randomly distributed silane coated hollow microspheres has been prepared by standard impregnation and lamination techniques. Laminates made of this prepreg can be drilled cleanly for through holes and can be used as a substrate for surface mounted devices.

Flame retardant, low dielectric constant microsphere filled laminate

Disclosed are an electronic package and electronic package module. The module has a dielectric core with surface circuitization on at least one surface. The dielectric core is a composite having a thermoplastic layer interposed between two separate layers of thermoset adhesive, as epoxy dicyanate adhesive. The thermoplastic layer is preferably a polyimide. The adhesive is preferably an epoxy or dicyanate adhesive, for example a homogeneous film of thermoset resin, or a fiber reinforced thermoset resin, such as a polytetrafluorethylene reinforced epoxy or a glass fiber reinforced adhesive. The use of a thermoplastic polyimide layer interposed between adhesive layers provides a core that is particularly amenable to manufacture as a thin core.

Electronic circuit packages with tear resistant organic cores

Dicyanato diphenyl fluorinated alkane resin precursor compositions are modified by the addition of minor predetermined amounts of aromatic diepoxides having high epoxide equivalent weights in order to reduce the curing temperature of prepregs and laminates, such as circuit boards, while retaining low dielectric constants, heat stability and high flame retardance.

Aromatic dicyanate/aromatic diepoxy compositions, cured products and

A flexible electrical connection, and method for making such a connection, for mounting an electronic device, such as a semiconductor chip made primarily of silicon, on an organic substrate, such as a printed circuit board made of a glass material impregnated with epoxy resin, are disclosed. The flexible electrical connection comprises a circuit line attached to the surface of the organic substrate and having a floating terminus in a relatively low adhesive area of the organic substrate where it is desired to mount the electronic device on the organic substrate. The floating terminus includes a stress relief bend, and the flexible electrical connection relieves stresses, such as thermal stresses, which may otherwise damage the physical and/or electrical connection between the electronic device and the floating terminus of the flexible electrical connection when the electronic device is mounted on the surface of the organic substrate.

Flexible electrical connection and method of making same

4,4'-(Hexafluoroisopropylidene) bisphonol dicyanate and related compounds have reduced dielectric constant, reduced moisture absorption, and increase Tg making such compounds especially suitable for various electronic applications, such as circuit packaging or in forming prepregs and circuit boards.

Fluorine containing dicyanate resins

A method is disclosed for the visual inspection of electrical circuitry deposited in the layers of a multilayer printed circuit board wherein the dielectric layers of the multilayer board are prepared using a clear, light transparent thermosetting resin having incorporated therein a dye which is permeable to visible light but which absorbs light in the 320-440 nm region. The electrical circuitry in the board can be easily traced by an observer upon illumination of the board by visible light.

Method for visual inspection of multilayer printed circuit boards

A continuous method for the manufacture of a circuit board wherein a coating of a solvent-free thermosetting resin is applied to the surface of a metal foil. The resin coated foil is advanced into contact with a reinforcing cloth sheet layer to form a foil/cloth assembly. The assembly is continuously conveyed between a pair of endless belts revolving in opposite directions with mutually facing surfaces, the belts being heated to the curing temperature of the resin whereby the belts are pressed against the assembly to continuously compact the assembly and cure the resin to form a composite product which can then be circuitized from a printed circuit board.

Continuous process for the manufacture of printed circuit boards

A method for producing a resin rich epoxy-glass prepreg and laminate wherein the epoxy-glass prepreg is given a first pass through an impregnation tower and impregnated with dicyandiamide cured brominated bisphenol type epoxy modified with a polyfunctional additive and advanced to 80-85% of complete cure. The prepreg is given a second pass through the tower and given a dip coating of, for example, brominated bisphenol A which is advanced to 80-85% of complete cure. The resulting prepreg serves as the outer sheet of a multi-layer printed circuit board and it has a resin rich surface necessary for chemical roughening and subsequent additive plating.

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Endwell, NY, United States of America

William J Summa