International Business Machines Corporation

Bruce John Chamberlin

Joseph Paul Kuczynski

Scott B King

Matthew Stephen Kelly

Thomas-Michael Winkel

James R Stack

Mitchell G Ferrill

David John Russell

Andreas Huber

William Louis Brodsky

John M Lauffer

James A Busby

Harald Huels

Robin A Susko

Voya Rista Markovich

Mark Kenneth Hoffmeyer

Wai Mon Ma

Paula M Nixa

Donald O Anstrom

Eric J Campbell

Sarah K Czaplewski

Wiren Dale Becker

Erich Klink

James Robert Wilcox

Roland Frech

Roger Scott Krabbenhoft

Arch F Nuttall

Douglas Oliver Powell

David L Thomas

Thomas Strach

James W Fuller, Jr

George A Katopis

Joseph P Resavy

Chang-Min Chu

Gao-Bin Hu

Kaspar Ka Chung Tsang

Jason T Wertz

Matthew Stephen Doyle

David Clifford Long

Eric Vance Kline

Jing Zhang

Prabjit Singh

David L Questad

David L Edwards

Sushumna Iruvanti

Sarah K Czaplewski-Campbell

Li Li

Peter Jeffrey Brofman

Thomas J Fleischman

Ahmad D Katnani

Timothy Matthew Trifilo

Randall Joseph Stutzman

George Henry Thiel

Jennifer V Muncy

Gerald J Fahr

Mark Budman

Brian L Carlson

Wayne J Rothschild

Dierk Kaller

Scott A Cummings

Jeffrey A Taylor

Michael J Griffin, Iv

Simone Rehm

Gregory S Killinger

Andreas Rebmann

Erica Elizabeth Jasper Gant

Helmut Virag

A method for fabricating an asymmetric printed circuit board with minimized warpage. The method includes determining a first resin area and a second resin area in a stack of printed circuit board layers. The method further includes performing computer modeling to predict a warpage of the printed circuit board layers during a predicted use of the printed circuit board layers. The method further includes determining a first target coefficient of thermal expansion for the first resin area and a second target coefficient of thermal expansion for the second resin area based on the computer modeling. The method further includes differentially curing resin in the first resin area and the second resin area based on the first target coefficient of thermal expansion and the second target coefficient of thermal expansion. The method further includes forming an asymmetric printed circuit board from the stack of printed circuit board layers.

Fabricating an asymmetric printed circuit board with minimized warpage

A process of manufacturing a multiple-layer printed circuit board includes selectively applying a dielectric resin to a region of a circuitized core layer. The process also includes partially curing the dielectric resin prior to performing a lamination cycle to form the multiple-layer printed circuit board that includes the circuitized core layer.

Selective dielectric resin application on circuitized core layers

Fabrication of a reliable circuit board assembly with soldered, plated through-hole structures is facilitated by characterizing plating of a plated through-hole of the circuit board using time-domain reflectance to obtain a base reflectance measurement, and applying solder to the plated through-hole. Based on applying the solder, the plating of the plated through-hole of the circuit board is re-characterized using time-domain reflectance to obtain a new reflectance value. Based on a deviation between the new reflectance measurement and the base reflectance measurement exceeding a threshold, dissolution, at least in part, of the plating of the plated through-hole due to applying the solder is identified.

Non-destructive identifying of plating dissolution in soldered, plated through-hole

According to one aspect, a glass-free pre-impregnated material includes a polybenzimidazole (PBI) sheet and a partially cured resin encapsulating the PBI sheet. According to another aspect, a process of forming a glass-free pre-impregnated material includes encapsulating a PBI sheet within a resin and partially curing the resin to form the glass-free pre-impregnated material. According to yet another aspect, a printed circuit board comprises a glass-free dielectric layer that includes a PBI sheet encapsulated within a cured resin.

Glass-free dielectric layers for printed circuit boards

A system for manufacturing a product includes a mating connector connected to solder pins to provide an electrical conducting path, the solder pins being aligned against solder pads so that each solder pin is thermally and electrically connected to its corresponding solder pad by a solder paste bead. The system also includes a controller to adjust electrical resistive heating of a solder paste bead during a soldering process according to a temperature of the solder paste bead. A method of manufacturing a product includes aligning the solder pins against the solder pads, connecting the mating connector to the solder pins, and heating a solder paste bead by an electrical resistive heating, the solder paste bead undergoing a soldering process, where a temperature of the solder paste bead is being evaluated and the electrical resistive heating is adjusted according to the temperature of the solder paste bead.

Manufacturing a product using a soldering process

A process of improving resistance to conductive anodic filament (CAF) formation is disclosed. The process includes dissolving a base resin material, a lubricant material, and a coupling agent in a solvent to form a functionalized sizing agent solution. The process also includes applying the functionalized sizing agent solution to individual glass fibers following a glass fiber formation process. The process further includes removing the solvent via a thermal process that partially converts the base resin material. The thermal process results in formation of coated glass fibers having a flowable resin coating that is compatible with a pre-impregnated (prepreg) matrix material utilized to form a prepreg material for manufacturing a printed circuit board. During one or more printed circuit board manufacturing operations, the flowable resin coating flows to fill voids between the individual glass fibers that represent CAF formation pathways.

Glass fiber coatings for improved resistance to conductive anodic filament formation

A glass fiber cloth includes a first warp glass fiber, a second warp glass fiber, and a weft glass fiber. The second warp glass fiber is adjacent to the first warp glass fiber. The weft glass fiber is overlaid over the first warp glass fiber and the second warp glass fiber. The weft glass fiber is attached to the first warp glass fiber.

Glass cloth including attached fibers

A compliant pin system includes a pin having a compliant section including a first leg and an opposing second leg. A first plurality of contact members extend along the first leg. A second plurality of contact members extend along the second leg. A pin validation system is operatively connected to the first plurality of contact members and the second plurality of contact members. The pin validation system detects a presence of an electrical signal passing between corresponding pairs of the first plurality of contact members and the second plurality of contact members to determine an integrity of the compliant pin.

Compliant pin with self sensing deformation

A process of in-situ detection of hollow fiber formation includes immersing a plurality of individual glass fibers in an index-matching material. The index-matching material has a first refractive index that substantially matches a second refractive index of the glass fibers. The process also includes exposing the individual glass fibers to a light source during immersion in the index-matching material. The process further includes utilizing one or more optical components to collect optical data for the individual glass fibers during immersion in the index-matching material. The process also includes determining, based on the optical data, that a particular glass fiber of the plurality of individual glass fibers includes a hollow fiber.

In-situ detection of glass fiber defects

A stubless via in printed wiring board may comprise one or more core layers. At least one core layer may be circuitized by including a copper trace and at least two other core layers may include copper laminations. The stubless via may further comprise one or more prepreg layers. The prepreg layers may be alternatively stacked between the core layers. the stubless via may further comprise a via. the via may be drilled through each of the alternatively stacked prepreg layers and core layers, exposing internal portions of the prepreg layers and core layers drilled through.

Via stub elimination by disrupting plating

A PWB may be drilled forming a via. The via may expose one or more internal portions of a core layer, a prepreg layer, and an anti-plate coating. A seed material may then be applied from a top portion of the PWB to the via, forming a seed layer in the via, the seed material not adhering to the anti-plate coating. Electroless metal may then be applied from the top portion of the PWB to the via, forming an electroless plate layer that adheres to the seed layer. Electrolytic copper may then be applied from the top portion of the PWB to the via, forming a copper layer that adheres to the electroless plate layer. A bottom portion of the electroless plate layer may then be removed.

An immersion weaving system includes a first drum immersed in a first bath of a liquid. The first drum is configured to form a glass strand from individual glass filaments. The immersion weaving system also includes a second drum immersed in the first bath of the liquid. The second drum is configured to form a yarn spool from the glass strand. The immersion weaving system further includes a loom immersed in a second bath of the liquid. The loom is configured to form a void-free glass cloth.

Liquid immersion techniques for improved resistance to conductive anodic filament formation

In-situ detection of hollow glass fiber formation

A component having a coating comprising a material in a first phase (e.g., solid and/or liquid phase) with a transition temperature. The component is mechanically and/or electrically attached to a substrate. Exposure of the coating to a temperature that meets or exceeds the transition temperature causes the material to undergo a phase change. The phase change of the material alters the position of the component, including separation of the component from the substrate. The separation disrupts the attachment, thereby mitigating damage to the substrate and/or component.

Coating for limiting substrate damage due to discrete failure

An apparatus is configured with a component having a coating comprising a material in a first phase (e.g., solid and/or liquid phase) with a transition temperature. The component is mechanically and/or electrically attached to a substrate. Exposure of the coating to a temperature that meets or exceeds the transition temperature causes the material to undergo a phase change. The phase change of the material alters the position of the component, including separation of the component from the substrate. The separation disrupts the attachment, thereby mitigating damage to the substrate and/or component.

Growing community of inventors

Vestal, NY, United States of America

Bruce John Chamberlin