International Business Machines Corporation

Michael G McMaster

Burton Jesse Carpenter

Logan L Simpson

Joseph LaTorre

Charles H Crockett, Jr

Karl G Hoebener

Ku Ho Chong

Stephen Alan Dunn, Deceased

Robert David Allen

Wayne Martin Moreau

Gregory Michael Wallraff

William R Brunsvold

William D Hinsberg, Iii

Melvin W Montgomery

Steven A Duncan

David W Malone

Stephen A Dunn

Robert J Tweig

A method of manufacturing a multiple layer circuit board with stacked vias of fine dimension and pitch. A base laminate with conductive pattern is coated with a dielectric which is photolithographically processed to create holes exposing selected regions of the underlying conductive pattern. The holes through the dielectric are plated to form via connections between the surface and the conductive pattern on the base laminate. The recess created by the via is filled with a conductive and plateable polymer which upon curing forms a conductive plug. A second dielectric layer is deposited on the board structure and in succession photolithographically processed to expose the underlying plated via and plug. The hole in the second dielectric is plated and filled with conductive polymer so as to create a second via vertically aligned with and electrically connected to the underlying first via. The ability to form fine pitch stacked vias is particularly important for printed circuit board structures such as carriers of flip chip die, in that the fine pitch of the solder ball array of the flip chip needs to be expanded and/or disbursed through multiple board layers with minimum area and electrical degradation.

Method of manufacturing a multiple layer circuit board die carrier with

Fine dimension stacked vias for a multiple layer circuit board structure

A method of reworking a printed circuit board having a surface including areas needing to be reworked including the steps of covering the surface with a dielectric leaving uncovered at least the areas of the surface to be reworked, and selectively providing corrective circuitry on the dielectric interconnected to the uncovered areas of the surface needing to be reworked. In addition, a printed circuit board having a surface including reworked areas including a dielectric covering the surface leaving uncovered at least the reworked areas, and corrective circuitry on the dielectric interconnected to the uncovered reworked areas.

Method and apparatus for reworking printed circuit boards using surface

A positive acting photoresist comprising a film forming reactive polymer; an iodonium initiator or a non-ionic compound that generates triflic acid upon exposure to radiation; and a multifunctional organic carboxylic acid is provided as well as use thereof.

Positive photoresist composition containing photoacid generator and use

Disclosed is a positive photoresist. The photoresist has as its polymeric component a substantially water and base insoluble, photolabile polymer. The photoresist further includes a photo acid generator that is capable of forming a strong acid. This photo acid generator may be a sulfonate ester derived from a N-hydroxyamide, or a N-hydroxyimide. Finally, the photoresist composition includes an appropriate photosensitizer.

Positive photoresist system for near-UV to visible imaging

A method and composition are shown for producing a positive-acting photoimagible epoxy resin. In addition to the epoxy resin, the compositions include a dual component cross-linking system which combines a basic curing agent with an onium or arylonium salt. The onium or arylonium salt produces a protic acid upon exposure to irradiation causing a reaction with the basic curing agent which renders the agent ineffective as an epoxy curing agent during subsequent heating. During a subsequent bake operation, only the unexposed regions of the epoxy will cross-link. As a result, the exposed areas wash away, leaving only the cured reverse image.

Method and composition for obtaining image reversal in epoxy

Growing community of inventors

Austin, TX, United States of America

Michael G McMaster