# US 10,481,496 B2 · Forming conductive vias using a light guide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,496 B2 - Document ID: US10481496B2 - Status: Granted - Kind: B2 - Application number: 15/635,374 - Filed: 2017-06-28 - Published: 2019-01-03 - Granted: 2019-11-19 - Earliest claimed: 2017-06-28 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Gerald Bartley; Matthew Doyle; Darryl Becker; Mark Jeanson - Web page: https://patentgrep.com/patent/US10481496B2 ## CPC - G03F 7/20: Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) - G03F 1/38: Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof - G03F 7/038: Macromolecular compounds which are rendered insoluble or differentially wettable (G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021) - G03F 7/039: Macromolecular compounds which are photodegradable, e.g. positive electron resists (G03F7/075 takes precedence; macromolecular quinonediazides G03F7/023) - G03F 7/16: Coating processes; Apparatus therefor (applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74) - G03F 7/26: Processing photosensitive materials; Apparatus therefor (G03F7/12 - G03F7/24 take precedence) - G03F 7/405: {Treatment with inorganic or organometallic reagents after imagewise removal} - H05K 3/4038: {Through-connections; Vertical interconnect access [VIA] connections (H05K3/403, H05K3/42 take precedence)} - H05K 3/428: {initial plating of through-holes in substrates having a metal pattern} - H05K 3/424: {by direct electroplating} - H05K 3/429: {Plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit layers} - H05K 2201/09645: Patterning on via walls; Plural lands around one hole - H05K 2203/0514: Photodevelopable thick film, e.g. conductive or insulating paste - H05K 2203/0562: Details of resist - H05K 2203/1383: Temporary protective insulating layer - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract The present invention provides a process and a structure of forming conductive vias using a light guide. In an exemplary embodiment, the process includes providing a via in a base material in a direction perpendicular to a plane of the base material, applying a photoresist layer to an interior surface of the via, inserting a light guide into the via, exposing, by the light guide, a portion of the photoresist layer to light, thereby resulting in an exposed portion of the photoresist layer and an unexposed portion of the photoresist layer, removing a portion of the photoresist layer, and plating an area of the via, where the photoresist has been removed, with a metal, thereby resulting in a portion of the via plated with metal and a portion of the via not plated with metal. ## Claims ### Claim 1 A process comprising: providing a via in a base material in a direction perpendicular to a plane of the base material; applying a photoresist layer to an interior surface of the via; inserting a light guide into the via; exposing, by the light guide, a portion of the photoresist layer to light, thereby resulting in an exposed portion of the photoresist layer and an unexposed portion of the photoresist layer; removing a portion of the photoresist layer; and plating an area of the via, where the photoresist has been removed, with a metal, thereby resulting in a portion of the via plated with metal and a portion of the via not plated with metal. ### Claim 2 (depends on 1) The process of claim 1, wherein a portion of an outer surface of the light guide is masked. ### Claim 3 (depends on 1) The process of claim 1, wherein the photoresist layer is a positive tone photoresist material. ### Claim 4 (depends on 3) The process of claim 3, wherein the removing comprises removing the exposed portion of the photoresist layer. ### Claim 5 (depends on 1) The process of claim 1 wherein the removing comprises washing the via with a photoresist developer. ### Claim 6 (depends on 1) The process of claim 1, wherein the photoresist layer is a negative tone photoresist material. ### Claim 7 (depends on 6) The process of claim 6, wherein the removing comprises removing the unexposed portion of the photoresist layer. ### Claim 8 A process comprising: providing a via in a base material, comprising at least two copper lines and at least one insulator layer separating the at least two copper lines, in a direction perpendicular to a plane of the base material, wherein the via intersects the at least two copper lines; applying a photoresist layer to an interior surface of the via; inserting a light guide into the via, wherein a portion of an outer surface of the light guide is masked; exposing, via the light guide, a portion of the photoresist layer to light, thereby resulting in an exposed portion of the photoresist layer and an unexposed portion of the photoresist layer; removing a portion of the photoresist layer; and plating an area of the via, where the photoresist has been removed, with a metal, thereby resulting in a portion of the via plated with metal and a portion of the via not plated with metal. ### Claim 9 (depends on 8) The process of claim 8, wherein the masked portion of the light guide has two or more masked regions separated by one or more unmasked regions. ### Claim 10 (depends on 8) The process of claim 8, wherein the photoresist layer is a positive tone photoresist material. ### Claim 11 (depends on 10) The process of claim 10, wherein the removing comprises removing the exposed portion of the photoresist layer. ### Claim 12 (depends on 8) The process of claim 8 wherein the removing comprises washing the via with a photoresist developer. ### Claim 13 (depends on 8) The process of claim 8, wherein the photoresist layer is a negative tone photoresist material. ### Claim 14 (depends on 13) The process of claim 13, wherein the removing comprises removing the unexposed portion of the photoresist layer. ### Claim 15 A process comprising: providing a via in a base material, comprising at least two copper lines and at least one insulator layer separating the at least two copper lines, in a direction perpendicular to a plane of the base material, wherein the via intersects the at least two copper lines; applying a photoresist layer to an interior surface of the via; inserting a light guide into the via; exposing, via the light guide, a portion of the photoresist layer to light, thereby resulting in an exposed portion of the photoresist layer and an unexposed portion of the photoresist layer; removing a portion of the photoresist layer; and plating an area of the via, where the photoresist has been removed, with a metal, thereby resulting in a portion of the via plated with metal and a portion of the via not plated with metal. ### Claim 16 (depends on 15) The process of claim 15, wherein a portion of an outer surface of the light guide is masked. ### Claim 17 (depends on 15) The process of claim 15, wherein the photoresist layer is a positive tone photoresist material. ### Claim 18 (depends on 17) The process of claim 17, wherein the removing comprises removing the exposed portion of the photoresist layer. ### Claim 19 (depends on 15) The process of claim 15 wherein the removing comprises washing the via with a photoresist developer. ### Claim 20 (depends on 15) The process of claim 15, wherein the photoresist layer is a negative tone photoresist material. ### Claim 21 (depends on 20) The process of claim 20, wherein the removing comprises removing the unexposed portion of the photoresist layer.