# US 2014/0190729 A1 · Flexible Printed Circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190729 A1 - Document ID: US20140190729A1 - Status: Published application - Kind: A1 - Application number: 13/734,189 - Filed: 2013-01-04 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Bose Corporation - Inventors: Drew Stone Briggs; Scott C. Perzanoski - Web page: https://patentgrep.com/patent/US20140190729A1 ## CPC - H05K 1/028: {Bending or folding regions of flexible printed circuits (H05K1/0283 takes precedence)} - H05K 1/0225: {Single or multiple openings in a shielding, ground or power plane (H05K1/0227 takes precedence)} - H05K 1/0218: {by printed shielding conductors, ground planes or power plane (H05K1/0236 takes precedence)} - H05K 1/0298: {Multilayer circuits} - H05K 3/4617: {characterized by laminating only or mainly similar single-sided circuit boards} - H05K 3/4635: {laminating flexible circuit boards using additional insulating adhesive materials between the boards} - H05K 2201/0715: provided by an outer layer of PCB - H05K 2201/09681: Mesh conductors, e.g. as a ground plane - H05K 2201/2009: Reinforced areas, e.g. for a specific part of a flexible printed circuit - Y10T 156/10: Methods of surface bonding and/or assembly therefor - Y10T 156/1043: Subsequent to assembly - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A flexible printed circuit includes a first insulating substrate layer and a first electrically conductive layer located adjacent to a first side of the insulating substrate layer. The first conductive layer has a first portion that is substantially solid and a second portion having a multiplicity of voids in the first conductive layer in a pattern for providing a lower stiffness in the second portion relative to the first portion, thereby providing more flexibility in the second portion relative to the first portion. ## Claims ### Claim 1 A flexible printed circuit, comprising: a first insulating substrate layer; and a first electrically conductive layer located adjacent to a first side of the insulating substrate layer, the first conductive layer having a first portion that is substantially solid and a second portion having a multiplicity of voids in the first conductive layer in a pattern for providing a lower stiffness in the second portion relative to the first portion, thereby providing more flexibility in the second portion relative to the first portion. ### Claim 2 (depends on 1) The flexible printed circuit of claim 1, further including a second electrically conductive layer comprising a plurality of electrically conductive traces for conducting one or more of electrical signals and electrical power from a first part of the flexible printed circuit to a second part of the flexible printed circuit, the second conductive layer being located adjacent to a second side of the insulating substrate layer. ### Claim 3 (depends on 1) The flexible printed circuit of claim 1, wherein the first electrically conductive layer includes a plurality of electrically conductive traces for conducting one or more of electrical signals and electrical power from a first part of the flexible printed circuit to a second part of the flexible printed circuit ### Claim 4 (depends on 1) The flexible printed circuit of claim 1, wherein the first conductive layer is made of copper. ### Claim 5 (depends on 1) The flexible printed circuit of claim 1, wherein an adhesive layer is located between the first conductive layer and the insulating layer. ### Claim 6 (depends on 2) The flexible printed circuit of claim 2, wherein an adhesive layer is located between the second conductive layer and the insulating layer. ### Claim 7 (depends on 1) The flexible printed circuit of claim 1, wherein the voids each have a cross-section that is substantially square in shape. ### Claim 8 (depends on 2) The flexible printed circuit of claim 2, wherein the first conductive layer resists electromagnetic radiation from traveling between the traces and an environment external to the flexible printed circuit. ### Claim 9 (depends on 2) The flexible printed circuit of claim 2, further including a second insulating layer, the first conductive layer being located adjacent to a first side of the second insulating layer; and a third electrically conductive layer located adjacent to a second side of the second insulating layer, the third conductive layer having a first portion that is substantially solid and a second portion having a multiplicity of voids in the third conductive layer in a pattern for providing a lower stiffness in the second portion of the third conductive layer relative to the first portion of the third conductive layer, thereby providing more flexibility in the second portion of the third conductive layer relative to the first portion of the third conductive layer. ### Claim 10 A method of manufacturing a flexible printed circuit , comprising: providing an insulating layer; supplying a first electrically conductive layer comprising a plurality of electrically conductive traces which will be used to conduct one or more of electrical signals and electrical power from a first portion of the flexible printed circuit to a second portion of the flexible printed circuit; securing the first conductive layer adjacent to a first side of the insulating layer; supplying a substantially solid second electrically conductive layer having a first portion and a second portion; creating a multiplicity of voids in the second portion of the conductive layer in a pattern for providing a lower stiffness in the second portion relative to the first portion; and securing the second conductive layer adjacent to a second side of the insulating layer, thereby controlling the flexibility of the flexible printed circuit. ### Claim 11 (depends on 10) The method of claim 10, further comprising: bending a second portion of the flexible printed circuit that includes the second portion of the second conductive layer relative to a first portion of the flexible printed circuit that includes the first portion of the second conductive layer, such that at least part of each of the first and second portions of the flexible printed circuit are located in different planes. ### Claim 12 (depends on 10) The method of claim 10, wherein the voids have a cross-section that is substantially square in shape. ### Claim 13 (depends on 10) The method of claim 10, wherein the second conductive layer resists electromagnetic radiation from traveling between the traces and an environment external to the flexible printed circuit. ### Claim 14 (depends on 10) The method of claim 10, wherein the insulating layer includes polyimide. ### Claim 15 An electrical apparatus that includes a flexible printed circuit, comprising: a first electrically conductive layer comprising a plurality of electrically conductive traces for conducting one or more of electrical signals and electrical power from a first portion of the flexible printed circuit to a second portion of the flexible printed circuit; a first insulating layer which substantially does not conduct electricity, the first conductive layer being located adjacent to a first side of the insulating layer; and a second electrically conductive layer located adjacent to a second side of the insulating layer, the second conductive layer having a first portion that is substantially solid and a second portion having a multiplicity of voids in the conductive layer in a pattern for providing a lower stiffness in the second portion relative to the first portion, a second portion of the flexible printed circuit that includes the second portion of the second conductive layer being bent relative to a first portion of the flexible printed circuit that includes the first portion of the second conductive layer, such that the first and second portions of the flexible printed circuit are located in different planes. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the voids have a cross-section that is substantially square in shape. ### Claim 17 (depends on 15) The apparatus of claim 15, wherein the second conductive layer resists electromagnetic radiation from traveling between the traces and an environment external to the flexible printed circuit. ### Claim 18 (depends on 15) The apparatus of claim 15, wherein a first adhesive layer is located between the first conductive layer and the insulating layer. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein a second adhesive layer is located between the second conductive layer and the insulating layer. ### Claim 20 (depends on 15) The apparatus of claim 15, further including a second insulating layer which substantially does not conduct electricity, the first conductive layer being located adjacent to a first side of the second insulating layer; and a third electrically conductive layer located adjacent to a second side of the second insulating layer, the third conductive layer having a first portion that is substantially solid and a second portion having a multiplicity of voids in the third conductive layer in a pattern for providing a lower stiffness in the second portion of the third conductive layer relative to the first portion of the third conductive layer, the second portion of the flexible printed circuit that includes the second portion of the third conductive layer being bent relative to the first portion of the flexible printed circuit that includes the first portion of the third conductive layer.