# US 11,645,490 B2 · Method for manufacturing personalized chipless radiofrequency identification (“RFID”) devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,645,490 B2 - Document ID: US11645490B2 - Status: Granted - Kind: B2 - Application number: 16/971,093 - Filed: 2019-03-06 - Published: 2020-12-17 - Granted: 2023-05-09 - Earliest claimed: 2018-03-08 - Assignees: MGI Digital Technology; Inkjet Engine Technology - Applicants: Mgi Digital Technology; Inkjet Engine Technology - Inventors: Edmond Abergel; Louis Gautier Le Boulch - Web page: https://patentgrep.com/patent/US11645490B2 ## CPC - G06K 19/0672: {with resonating marks} - G06K 19/07722: {the record carrier being multilayered, e.g. laminated sheets (flat articles in general, see B32B37/00)} - G06K 19/067: Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards {also with resonating or responding marks without active components} - H05K 1/0242: {Structural details of individual signal conductors, e.g. related to the skin effect} - H05K 1/0298: {Multilayer circuits} - H05K 3/046: {by selective transfer or selective detachment of a conductive layer} - H05K 3/12: using {thick film techniques, e.g.} printing techniques to apply the conductive material {or similar techniques for applying conductive paste or ink patterns} - H05K 2201/10098: Components for radio transmission, e.g. radio frequency identification [RFID] tag, printed or non-printed antennas - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract The present invention relates to a method for producing radio frequency identification devices (RFID) without personalized chip, in particular the production of RFID tags without personalized chip, also referred to as chipless RFID tags. The present invention also relates to devices and labels produced by the claimed method as well as to systems for producing said devices/labels. ## Claims ### Claim 1 A chipless radiofrequency identification device, said device being characterized by a multilayer composition comprising a substrate, a pattern printed digitally on the substrate and consisting of a printing product comprising an ink, a varnish and/or a toner, an identical pattern superimposed on the printed pattern and consisting of a conductive film comprising an application film layer in contact with the printing product and a conductive film layer, the conductive film configured to reflect a radiofrequency signature indicative of information coded on the chipless radiofrequency identification device only by resonant backscattering of the conductive film. ### Claim 2 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the printed pattern is a dielectric. ### Claim 3 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the thickness of the printed pattern is greater than 3 microns and less than 200 microns. ### Claim 4 (depends on 3) The chipless radiofrequency identification device as claimed in claim 3, characterized in that the thickness of the printed pattern is greater than 10 microns and less than 100 microns. ### Claim 5 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the thickness “e” of the printed pattern is between 0.9.e and 1.1.e over its entire surface area. ### Claim 6 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the conductive film layer thickness is greater than 100 nm. ### Claim 7 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the conductive film layer thickness is greater than 500 nm. ### Claim 8 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the conductive film layer thickness is less than 2 microns. ### Claim 9 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the conductive film layer is characterized by a surface resistance property of less than 1 ohm per square. ### Claim 10 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the printing product and the application film layer comprise a thermoplastic material. ### Claim 11 (depends on 10) The chipless radiofrequency identification device as claimed in claim 10, characterized in that the thermoplastic material of the application film layer is characterized by a glass transition temperature value “Tg” of between 40° C. and 80° C. and in that the thermoplastic material of the printing product is characterized by a Tg value of between 10 and 50° C. ### Claim 12 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, further comprising an interstitial layer comprising material of the printing product and material of the application film layer of the film. ### Claim 13 (depends on 1) The chipless radiofrequency excitation identification device as claimed in claim 1, wherein the conductive film layer thickness is less than 2.5 times a skin thickness at a given frequency, said skin thickness being able to be calculated using the formula δ = 2 ω ⁢ ⁢ μσ = 2 ⁢ ρ ωμ = 1 σμπ ⁢ ⁢ f where δ is the skin thickness in meters [m], f is the frequency of the current in hertz [Hz], ω is the angular frequency in radians per second [rad/s] (ω=2.π.f) σ is the electrical conductivity in siemens per meter [S/m] ρ is the resistivity in ohm-meters [Ω.m] (ρ=1/σ), and μ is the magnetic permeability in henries per meter [H/m], this permeability having the value 4σ10−7 for a vacuum. ### Claim 14 (depends on 13) The chipless radiofrequency excitation identification device as claimed in claim 13, characterized in that the excitation frequency is selected from a frequency band between 3 GHz and 10 GHz. ### Claim 15 (depends on 1) The chipless radiofrequency identification device as claimed in claim 1, characterized in that the conductive film layer thickness is less than 0.75 microns. ### Claim 16 A method for manufacturing a chipless radiofrequency identification device including a multilayer composition comprising a substrate, the method comprising: a step of digitally printing a pattern on the substrate by printing a printing product comprising an ink, a varnish and/or a toner, followed by a step of selectively depositing a conductive film on the printed pattern through contact between the printing product and the application film layer of the conductive film comprising an application film layer in contact with the printing product and a conductive film layer, the conductive film configured to reflect a radiofrequency signature indicative of information coded on the chipless radiofrequency identification device only by resonant backscattering of the conductive film. ### Claim 17 (depends on 16) The method for manufacturing chipless radiofrequency identification devices as claimed in claim 16, characterized in that the step of digitally printing the pattern is performed through varnish/ink inkjet printing or through toner electrophotography (xerography) printing. ### Claim 18 (depends on 16) The method for manufacturing chipless radiofrequency identification devices as claimed in claim 16, characterized in that the RF signature of the radiofrequency identification device is controlled by selecting the shape of the conductive pattern and/or by selecting the type of printing product and/or by selecting the thickness of the printing product.