International Business Machines Corporation

Mark L Janecek

Voya Rista Markovich

Frank Daniel Egitto

David John Russell

Luis Jesus Matienzo

Elizabeth F Foster

David Erle Houser

Raymond Thomas Galasco

Jeffrey Alan Knight

Stephen Wesley MacQuarrie

Thomas E Kindl

Amarjit S Rai

William T Wike

A method for detecting misalignment of layers of a multi-layer circuit board. A plurality of layers of electrically insulating material are formed. At least one artwork feature is formed on a surface of at least one of the layers of electrically insulating material in the vicinity of at least one edge of the at least one layer of electrically insulating material. At least one reference point is formed on the at least one layer of electrically insulating material. The layers of electrically insulating material are joined together. The at least one artwork feature is exposed by removing a portion of the at least one layer of electrically insulating material. A location of the at least one artwork feature relative to the at least one reference point is visually determined, thereby detecting misalignment of the layers of electrically insulating material.

Method for making multi-layer printed circuit board registration

A method and structure for forming a metalized blind via. A dielectric layer is formed on a metallic layer, followed by laser drilling a depression in the dielectric layer such that a carbon film that includes the carbon is formed on a sidewall of the depression. If the laser drilling does not expose the metallic layer, then an anisotropic plasma etching, such as a reactive ion etching (RIE), may be used to clean and expose a surface of the metallic layer. The dielectric layer includes a dielectric material having a carbon based polymeric material, such as a permanent photoresist, a polyimide, and advanced solder mask (ASM). The metallic layer includes a metallic material, such as copper, aluminum, and gold. The carbon film is in conductive contact with the metallic layer, and the carbon film is sufficiently conductive to permit electroplating a continuous layer of metal (e.g., copper) directly on the carbon film without need of an electrolessly plated layer underneath the electroplated layer. The laser drilling is accomplished using a laser radiation having a wavelength between about 180 nanometers and about 600 nanometers. The depression may have any cross-sectional shape and any spatial distribution of depths. As an example, the depression may include a blind via, a rectangular channel, or a combination thereof.

Fabrication of a metalized blind via

A method and structure for forming a metalized blind via. A dielectric layer is formed on a metallic layer, followed by laser drilling a depression in the dielectric layer such that a carbon film that includes the carbon is formed on a sidewall of the depression. If the laser drilling does not expose the metallic layer, then an anisotropic plasma etching, such as a reactive ion etching (RIE), may be used to clean and expose a surface of the metallic layer. The dielectric layer comprises a dielectric material having a carbon based polymeric material, such as a permanent photoresist, a polyimide, and advanced solder mask (ASM). The metallic layer includes a metallic material, such as copper, aluminum, and gold. The carbon film is in conductive contact with the metallic layer, and the carbon film is sufficiently conductive to permit electroplating a continuous layer of metal (e.g., copper) directly on the carbon film without need of an electrolessly plated layer underneath the electroplated layer. The laser drilling is accomplished using a laser radiation having a wavelength between about 180 nanometers and about 600 nanometers. The depression may have any cross-sectional shape and any spatial distribution of depths. As an example, the depression may include a blind via, then the blind via may have any cross-sectional shape, such as circular or non-circular, a rectangular channel, or a combination thereof.

A Method for detecting misalignment of layers of a multi-layer circuit board. A Plurality of layers of electrically insulating material are formed. At least one artwork feature is formed on a surface of at least one of the layers of electrically insulating material in the vicinity of at least One edge of the at least one layer of electrically insulating material. At least one reference point is formed on the at least one layer of electrically insulating material. The layers of electrically insulating material are joined together. The at least one artwork feature is exposed by removing a portion of the at least one layer of electrically insulating material. A location of the at least one artwork feature relative to the at least one reference point is visually determined, thereby detecting misalignment of the layers of electrically insulating material.

Multi-layer printed circuit board registration

Growing community of inventors

Endicott, NY, United States of America

Mark L Janecek