# US 2018/0025806 A1 · Flexible flat cable > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0025806 A1 - Document ID: US20180025806A1 - Status: Published application - Kind: A1 - Application number: 15/436,105 - Filed: 2017-02-17 - Published: 2018-01-25 - Earliest claimed: 2016-07-25 - Assignees: Hee jun YOON - Inventors: Sang bo YOON - Web page: https://patentgrep.com/patent/US20180025806A1 ## CPC - H01B 7/0838: {Parallel wires, sandwiched between two insulating layers} - H01B 7/04: Flexible cables, conductors, or cords, e.g. trailing cables - H01B 7/295: using material resistant to flame - H03H 7/38: Impedance-matching networks - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract The present invention relates to a flexible flat cable including a plurality of conductive wires disposed between an upper film and a lower film, wherein an air gap is formed between the conductive wires. The flexible flat cable according to the present invention includes a plurality of conductive wires (15) disposed between an upper film (11) and a lower film (13), wherein the conductive wires (15) are fixed by a first thermal bonding resin (12) of the upper film (11) and a second thermal bonding resin (14) of the lower film (13), an air gap (16) is formed between the conductive wires (15), and a side end of the upper film (11) and a side end of the lower film (13) are bonded by the first thermal bonding resin (12) and the second thermal bonding resin (14). ## Claims ### Claim 1 A flexible flat cable including a plurality of conductive wires (15) disposed between an upper film (11) and a lower film (13), wherein the conductive wires (15) are fixed by a first thermal bonding resin (12) of the upper film (11) and a second thermal bonding resin (14) of the lower film (13), an air gap (16) is formed between the conductive wires (15), and a side end of the upper film (11) and a side end of the lower film (13) are bonded by the first thermal bonding resin (12) and the second thermal bonding resin (14). ### Claim 2 A flexible flat cable including a plurality of conductive wires (15) disposed between an upper film (11) and a lower film (13), wherein the conductive wires (15) are fixed by a first thermal bonding resin (12) applied to a lower surface of the upper film (11), an air gap (16) is formed between the conductive wires (15) and between the lower film (13) and the conductive wire (15), and a side end of the upper film (11) and a side end of the lower film (13) are bonded by the first thermal bonding resin (12). ### Claim 3 A flexible flat cable including a plurality of conductive wires (15) disposed between an upper film (11) and a lower film (13), wherein the conductive wires (15) are fixed by a second thermal bonding resin (14) applied to the lower film (13), an air gap (16) is formed between the conductive wires (15) and between the upper film (11) and the conductive wire (15), and a side end of the upper film (11) and a side end of the lower film (13) are bonded by the second thermal bonding resin (14). ### Claim 4 (depends on 1) The flexible flat cable of claim 1, wherein the conductive wires (15) have a height (h1) larger than a sum of a thickness (t2) of the first thermal bonding resin (12) and a thickness (t3) of the second thermal bonding resin (14), so that the air gap (16) is formed between the conductive wires (15). ### Claim 5 (depends on 2) The flexible flat cable of claim 2, wherein the air gap (16) is divided into a plurality of air gaps (16a, 16b, 16c, . . . ) by a plurality of partition portions (12a) formed at the first thermal bonding resin (12) and arranged between the conductive wires (15). ### Claim 6 (depends on 3) The flexible flat cable of claim 3, wherein the air gap (16) is divided into a plurality of air gaps (16a′, 16b′, 16c′, . . . ) by a plurality of partition portions (14a) formed at the second thermal bonding resin (14) and arranged between the conductive wires (15). ### Claim 7 (depends on 1) The flexible flat cable of claim 1, wherein the first thermal bonding resin (12) and the second thermal bonding resin (14) are hot-melt films. ### Claim 8 (depends on 1) The flexible flat cable of claim 1, wherein the air gap (16) is formed between signal transmission lines (15a and 15b) for transmitting signals, and a thermal bonding resin is filled between the signal transmission line (15a or 15b) and a ground line (16c) and between ground lines (16c). ### Claim 9 (depends on 1) The flexible flat cable of claim 1, wherein the conductive wires (15) have a rectangular or circular sectional shape. ### Claim 10 (depends on 1) The flexible flat cable of claim 1, wherein an impedance matching sheet (20) is attached to a lower surface of the lower film (13), an upper portion of the upper film (11), or both the upper portion of the upper film (11) and the lower surface of the lower film (13). ### Claim 11 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of the conductive wires (15) is equal to a length of the lower film (13), so that an end portion of the conductive wires (15) matches with an end portion of the lower film (13), the length (L1) of the conductive wires (15) is longer than a length (L2) of the upper film (11), so that an exposed connection end (17a) of the conductive wires (15) is exposed outward from an end portion of the upper film (11), a lower horizontal portion (18a) of a cover film (18) is bonded to the exposed connection end (17a) of the conductive wires (15) at the end portion of the upper film (11), and an upper horizontal portion (18b) of the cover film (18) is bonded to the upper film (11), so that the air gap is filled with an adhesive (19) thickly applied to the cover film (18) so as to prevent a plating solution from entering the air gap (16) in a plating process, and the adhesive (19) of the cover film (18) and the second thermal bonding resin (14) of the lower film (13) are bonded to surround the conductive wires (15). ### Claim 12 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of conductive wires (15) is longer than a length (L2) of the upper film (11) and a length (L3) of the lower film (13), so that an exposed connection end (17b) of the conductive wires (15) is exposed outward from an end portion of the upper film (11) and an end portion of the lower film (13), the length (L2) of the upper film (11) is longer than the length (L3) of the lower film (13), so that a second reinforcing plate (30) is simultaneously bonded to a lower surface of the exposed connection end (17b) and the end portion of the lower film (13), a part of the second reinforcing plate (30) overlaps with the end portion of the upper film (11), the air gap is filled with an adhesive (32) thickly applied to the second reinforcing plate (30), and the adhesive (32) and the first thermal bonding resin (12) of the upper film (11) are bonded to surround a periphery of the conductive wires (15) at the exposed connection end (17b). ### Claim 13 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of the conductive wires (15) is equal to a length of the lower film (13), so that an end portion of the conductive wires (15) matches with an end portion of the lower film (13), the length (L1) of the conductive wires (15) is longer than a length (L2) of the upper film (11), so that an exposed connection end (17c) of the conductive wires (15) is exposed outward from an end portion of the upper film (11), a thermal-pressed end (11a) for pressing the air gap is formed at the end portion of the upper film (11) by thermally pressing the end portion of the upper film (11) so as to prevent a plating solution from entering the air gap (16) in a plating process, and the first thermal bonding resin (12) applied to the thermal-pressed end (11a) of the upper film (11) and the second thermal bonding resin (14) of the lower film (13) are bonded to each other so as to surround a periphery of the conductive wires (15). ### Claim 14 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of the conductive wires (15) is longer than a length (L2) of the upper film (11) and a length (L3) of the lower film (13), so that an exposed connection end (17d) of the conductive wires (15) is exposed outward from an end portion of the upper film (11) and an end portion of the lower film (13), the length (L2) of the upper film (11) is longer than the length (L3) of the lower film (13), a second reinforcing plate (30) is bonded to a lower surface of the exposed connection end (17d) and the end portion of the lower film (13) and a thermal-pressed end (11a) for pressing the air gap is formed at the end portion of the upper film (11) by thermally pressing the end portion of the upper film (11) so as to prevent a plating solution from entering the air gap (16) in a plating process, and the first thermal bonding resin (12) applied to the thermal-pressed end (11a) of the upper film (11) and an adhesive (32) of the second reinforcing plate (30) are bonded to each other so as to surround a periphery of the conductive wires (15). ### Claim 15 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of the conductive wires (15) is equal to a length of the lower film (13), so that an end portion of the conductive wires (15) is matched with an end portion of the lower film (13), the length (L1) of the conductive wires (15) is longer than a length (L2) of the upper film (11), so that an exposed connection end (17e) of the conductive wires (15) is exposed outward from an end portion of the upper film (11), an air gap prevention film (40) is attached to an upper surface of the exposed connection end (17e) at the end portion of the upper film (11), a part of the air gap prevention film (40) is covered with a cover end portion (11b) of the upper film (11), and the air gap is filled with an adhesive (42) thickly applied to the air gap prevention film (40) so as to prevent a plating solution from entering the air gap (16) in a plating process, and the adhesive (42) of the air gap prevention film (40) and the second thermal bonding resin (14) of the lower film (13) are bonded to surround the conductive wires (15). ### Claim 16 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of the conductive wires (15) is longer than a length (L2) of the upper film (11) and a length (L3) of the lower film (13), so that an exposed connection end (17f) of the conductive wires (15) is exposed outward from an end portion of the upper film (11) and an end portion of the lower film (13), the length (L2) of the upper film (11) is longer than the length (L3) of the lower film (13), an air gap prevention film (40) is attached to a lower surface of the exposed connection end (17f) at the end portion of the lower film (13), a part of the air gap prevention film (40) is covered with a cover end portion (13b) of the lower film (13), and the air gap is filled with an adhesive (42) thickly applied to the air gap prevention film (40) so as to prevent a plating solution from entering the air gap (16) in a plating process, and the adhesive (42) of the air gap prevention film (40) and the first thermal bonding resin (12) of the upper film (11) are bonded to surround the conductive wires (15). ### Claim 17 (depends on 1) The flexible flat cable of claim 1, wherein a length (L1) of the conductive wires (15) is longer than a length (L2) of the upper film (11) and a length (L3) of the lower film (13), so that an exposed connection end (17g) of the conductive wires (15) is exposed outward from an end portion of the upper film (11) and an end portion of the lower film (13), the length (L2) of the upper film (11) is equal to the length (L3) of the lower film (13), a thermal-pressed end (11a) for pressing the air gap is formed at the end portion of the upper film (11) and a thermal-pressed end (13a) for pressing the air gap is formed at the end portion of the lower film (13) by heat-pressing the end portion of the upper film (11) and the end portion of the lower film (13) so as to prevent a plating liquid from entering the air gap (16) in a plating process, the first thermal bonding resin (12) applied to the thermal-pressed end (11a) of the upper film (11) and the second thermal bonding resin (14) applied to the thermal-pressed end (13a) of the lower film (13) are bonded to surround the conductive wires (15), and the second reinforcing plate (30) is bonded to a lower surface of the exposed connection end (17g) and the heat-pressed end (13a) of the lower film (13) by an adhesive (32). ### Claim 18 A flexible flat cable including a plurality of conductive wires (115) disposed between an upper film (111) and a lower film (113), wherein the conductive wires (115) are fixed by a first thermal bonding resin (112) of the upper film and a second thermal bonding resin (114) of the lower film, a first air gap (116) is formed between the conductive wires, a second air gap (126) is formed by removing the first thermal bonding resin on a partial upper surface of each of the conductive wires, a third air gap (136) is formed by removing the second thermal bonding resin on a partial lower surface of each of the conductive wires, and a side end of the upper film and a side end of the lower film are bonded by the first thermal bonding resin (112) and the second thermal bonding resin (114). ### Claim 19 (depends on 18) The flexible flat cable of claim 18, wherein the conductive wires have a height higher than a sum of a thickness of the first thermal bonding resin (112) and a thickness of the second thermal bonding resin (114), an upper surface of the first air gap (116) is formed at a position higher than the upper surface of the conductive wires (115), and a lower surface of the first air gap (116) is formed at a position lower than the lower surface of the conductive wires (115). ### Claim 20 (depends on 18) The flexible flat cable of claim 18, wherein the first thermal bonding resin (112) and the second thermal bonding resin (114) are hot-melt films. ### Claim 21 (depends on 18) The flexible flat cable of claim 18, wherein the first air gap (116), the second air gap (126), and the air third gap (136) are formed in a stripe shape. ### Claim 22 A flexible flat cable including a plurality of circular conductive wires (1115) disposed between an upper film (111) and a lower film (113), wherein the circular conductive wires are fixed by a first thermal bonding resin (112) of the upper film and a second thermal bonding resin (114) of the lower film, the first thermal bonding resin of the upper film and the second thermal bonding resin of the lower film are partially removed to form an air gap (1116) between the circular conductive wires such that the air gap is shielded from the circular conductive wires, and a side end of the upper film and a side end of the lower film are bonded to each other by the first thermal bonding resin (112) and the second thermal bonding resin (114). ### Claim 23 (depends on 22) The flexible flat cable of claim 22, wherein an impedance matching sheet (120) is selectively attached to the upper film and the lower film.