COMPONENTS HAVING ONE OR MORE CONDUCTIVE PATTERNS FOR ELECTRICAL, WIRELESS OR ELECTRONIC DEVICES AND DEVICES COMPRISING SUCH COMPONENTS

Abstract

The present invention relates to a component (1) for an electric, wireless or electronic device (2), comprising a substrate (3) provided with a dielectric surface (4) carrying a conductive pattern (5) having an inner surface in contact with the dielectric surface (4) and an opposite outer surface (5B), the conductive pattern being formed of a metal, the upper surface of the conductive pattern having a roughness Sa of 500 nm or less, the conductive pattern having a thickness (e) of 10 nm to 500 nm and a sheet resistance of 800 mΩ / □ or less. The present invention further relates to an electric, wireless or electronic device comprising such a component. Component with a conductive pattern; Electric, wireless or electronic device comprising a component with a conductive pattern.

Description

[Technical field]

[0001] The present invention relates to the general technical field of components for electrical, wireless or electronic devices, in particular radio frequency transmitter and / or receiver wireless devices or sensors / detectors, comprising a substrate provided with a dielectric surface carrying at least one conductive pattern.

[0002] The invention more particularly relates to a component for an electric, wireless or electronic device comprising a substrate provided with a dielectric surface carrying at least one conductive pattern, the conductive pattern having a lower surface in contact with the dielectric surface and an opposite upper surface, and also to an electric, wireless or electronic device comprising such a component. [Background technology]

[0003] In the field of components for electrical, wireless or electronic devices with conductive pattern(s), components manufactured by the so-called "printed electronics" technique, which consists in producing a conductive pattern on the surface of a substrate by printing (for example by inkjet or screen printing techniques) with conductive inks or pastes, have been known for many years. These conductive inks or pastes typically comprise a polymer liquid or paste phase in which particles of conductive material are dispersed. After printing, the deposited ink or paste is subjected to a drying / curing step, thereby forming a conductive pattern with a polymer matrix. Within the polymer matrix are trapped particles of conductive material that provide electrical conductivity to the formed pattern.

[0004] Among the devices integrating such components, radio frequency antennas such as RFID tags are known in particular, in which the antenna radiating element is formed by a conductive pattern printed on a dielectric substrate according to the above. Although such known devices and components are generally satisfactory, there is room for improvement with regard to controlling the conductive properties of their printed conductive patterns and therefore with regard to the radio performance level, in particular for applications in the radio frequency range from ultra high frequency (UHF) to terahertz frequencies (THz).

[0005] Furthermore, known devices and components may lack reliability and durability, and the properties of their printed conductive patterns tend to deteriorate over time under the influence of aging of the polymer matrix of the pattern, migration of particles of the conductive material, etc. This may cause, in particular, undesirable variations in the properties of the conductive pattern as a function of environmental variables (humidity, temperature, etc.). Furthermore, although the introduction of printed electronics technology has led to progress in terms of reduced manufacturing costs, weight reduction, and ease of integration of components, there is still much progress to be made in this field. In particular, the conductive inks used are still generally relatively expensive, and the patterns must be printed at a relatively large thickness to obtain sufficient conductivity. Summary of the Invention

[0006] The object assigned to the present invention is therefore to provide a response to the above-mentioned needs and problems and in particular to propose new components having conductive pattern(s) for electrical, wireless or electronic devices, whose conductive pattern(s) have excellent electrical properties and are in particular suitable for the manufacture of wireless devices operating at very high radio frequencies or electronic devices such as sensors.

[0007] Another object of the invention is to propose new components for electric, radio or electronic devices which have excellent electrical properties, but which are particularly space-saving and easy to integrate.

[0008] Another object of the invention is to propose new components for electrical, radio or electronic devices which have excellent electrical properties but are particularly cheap to manufacture.

[0009] Another object of the invention is to propose new components for electrical, radio or electronic devices which are particularly durable and reliable whilst having excellent electrical properties.

[0010] Another object of the invention is to propose new electrical, radio or electronic devices comprising components having conductive pattern(s) whose electrical, radio or electronic operation is particularly efficient.

[0011] Another object of the invention is to propose new electric, radio or electronic devices comprising components with conductive pattern(s) that are space-saving and easy to integrate.

[0012] Another object of the invention is to propose new electric, radio or electronic devices comprising components with conductive pattern(s) that are cheap to manufacture.

[0013] Another object of the invention is to propose new electric, wireless or electronic devices comprising components with durable and reliable conductive pattern(s).

[0014] Another object of the invention is to propose a new wireless device, such as a radio frequency transmitter and / or receiver device, in which the radio frequency antenna radiating element has a particularly high quality factor and radiation efficiency.

[0015] Another object of the invention is to propose a new electronic device forming a sensor / detector with excellent measurement resolution.

[0016] The object assigned to the present invention is achieved by using a component for an electric, radio or electronic device comprising a substrate provided with a dielectric surface carrying at least one conductive pattern, the conductive pattern having a lower surface in contact with the dielectric surface and an opposite upper surface, the component being characterized in that the conductive pattern is made of metal, the upper surface of the conductive pattern has a roughness Sa of less than or equal to 500 nm and the conductive pattern has a thickness between 10 nm and 500 nm.

[0017] The objects assigned to the present invention are further achieved by an electric, wireless or electronic device comprising such a component.

[0018] Other characteristics and advantages of the invention will appear in more detail on reading the following description, with reference to the attached drawings, given purely as illustrative and non-limiting examples, in which: [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 shows a schematic cross-sectional view of an example of a component according to the invention; [Diagram 2] FIG. 2 shows a schematic cross-sectional view of another example of a component according to the invention; [Diagram 3] FIG. 1 shows an example of a wireless device according to the present invention constituting a three-dimensional tag for a Radio Frequency Identification (RFID) system, where the conductive pattern forms an RFID radio frequency antenna radiating element. [Figure 4] FIG. 2 illustrates an example of a component for a wireless device according to the present invention, in which the conductive pattern forms a WiFi® dipole radio frequency antenna radiating element. [Diagram 5] FIG. 1 illustrates an example of a component for an electronic device such as a capacitive sensor in which a conductive pattern forms a capacitive sensor electrode. [Figure 6]An example of an electrical device according to the invention constituting a heated electrical device forming a heating / de-icing radome for a radio tracking system (proximity radar sensor) is shown, the conductive pattern of which forms a heating circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The invention first relates to a component 1 for an electric, wireless or electronic device 2, i.e. a functional element or subassembly designed to be integrated into an electric, wireless or electronic device 2 in order to provide (or at least contribute to the provision of) a particular electric, wireless or electronic function. The component 1 comprises a substrate 3 provided directly or indirectly with a dielectric surface 4 carrying at least one conductive pattern 5. Said substrate 3 thus forms a support for said conductive pattern 5. In this specification, a "dielectric surface" advantageously means a surface that is not conductive, i.e. electrically insulating, in particular a non-metallic surface. In this specification, a "conductive pattern" generally means a layer of conductive material adhering to the dielectric surface 4 and having a specific and specific shape selected having regard to the electrical, wireless or electronic function of the device 2 in which the component 1 is intended to participate. An example of a component 1 according to the invention is shown diagrammatically in Figs. 1 and 2. The invention also relates to an electric, wireless or electronic device 2 comprising such a component 1.

[0021] As shown diagrammatically in Figures 1 and 2, the conductive pattern 5 has a lower surface 5A in contact with the dielectric surface 4 and an opposite upper surface 5B. Advantageously, as shown diagrammatically in Figures 1 and 2, the upper surface 5B of the conductive pattern 5 is not in contact with said dielectric surface 4, but extends preferentially above said dielectric surface 4. According to a variant shown in Figure 1, the conductive pattern 5 is arranged in direct contact with the surface of the substrate 3. In this case, said substrate 3 is made of a dielectric material, the surface of the substrate 3 thus directly forming said dielectric surface 4. According to another variant shown in Figure 2, the surface of the substrate 3 is covered with an intermediate coating 6, for example a layer of varnish or a layer of primer, forming said dielectric surface 4 provided with said conductive pattern 5. The intermediate coating 6 is thus made of a dielectric material and has a lower surface that adheres to the surface of the substrate 3 and an opposite upper surface, thus advantageously forming the dielectric surface 4 carrying the conductive pattern 5. In such a variant, the substrate 3 may not itself be made of a dielectric material 4, which is nevertheless preferred.

[0022] Preferably, the substrate 3 is made of a polymer material, a composite or hybrid polymer matrix material, paper, glass, textiles, leather (animal (skin), vegetable or synthetic leather) or a ceramic material. Nevertheless, it is less preferred that the substrate 3 is a non-dielectric metallic material, but it is still considered on the assumption that the surface of the substrate 3 is covered with an intermediate coating 6 which is itself made of a dielectric material as considered above, whereby the intermediate coating 6 forms the dielectric surface 4 with which the conductive pattern 5 is placed in contact.

[0023] According to the invention, the conductive pattern 5 carried by the substrate 3 is made of metal, i.e. the conductive pattern 5 is thus formed of at least one elemental metal (or "elementary"), at least one mixture of elemental metals or at least one metal alloy, apart from any non-metallic impurities. That is to say, the conductive pattern 5 is formed of solid metal and forms a continuous metal layer. The top surface 5B of the conductive pattern 5 of the component 1 according to the invention also has a roughness Sa which is less than or equal to 500 nm. The "roughness Sa" (or "roughness parameter Sa") is an extension of the roughness parameter Ra for the surface ("roughness Ra" or "average arithmetic roughness" for the profile) and thus makes it possible to evaluate and characterize the average arithmetic roughness of a surface. The "roughness Sa" as well as the means and methods for measuring this "roughness Sa" are in particular defined in the standard ISO 25178:2016. For example, the roughness Sa can be measured with an atomic force microscope, by interferometry or also with a confocal probe. Furthermore, the conductive pattern 5 of the component 1 according to the present invention has a thickness e of 10 nm to 500 nm.

[0024] Interestingly, it has been observed that the particular combination of the above-mentioned characteristics regarding the configuration of the conductive pattern 5, the roughness Sa and the thickness e of the top surface 5B of the conductive pattern 5, provides the component 1 according to the invention with excellent electrical properties, in particular with regard to the uniformity of the conductivity / resistivity of the conductive pattern 5. Furthermore, the conductive pattern 5 being made of metal and the top surface 5B of the conductive pattern 5 having a roughness Sa of 500 nm or less, allows the top surface 5B to be provided with a high surface conductivity and a particularly smooth finish, which allows the conduction losses to be minimized. Furthermore, the thinness of the conductive pattern 5 allows for a particularly space-saving, easy integration of the component and a design with particularly low material costs.

[0025] In addition to allowing a particularly thin thickness e of the conductive pattern 5, the fact that the conductive pattern 5 is made of metal (or "solid metal") and not in the form of a composite polymer matrix material in which conductive particles, e.g. metal particles, are dispersed, as is the case in conventional printed electronics, advantageously provides the conductive pattern 5 with greater durability and reliability over time, since its conductive / resistive properties do not change significantly over time.

[0026] The component 1 according to the invention therefore allows in particular the manufacture of a wireless device 2, such as a radio frequency transmitter and / or receiver device, in which the conductive pattern 5 of the component 1 forms a radio frequency antenna radiating element with a particularly high quality factor and radiation efficiency, in particular for applications in the high frequency (HF), very high frequency (VHF), extremely high frequency (UHF), centimeter wave (SHF), millimeter wave (EHF) and terahertz (THz) frequency ranges. The component 1 according to the invention further allows the manufacture of an electronic device 2 forming a sensor / detector, in which the conductive pattern 5 of the component 1 forms a sensor / detector electrode with excellent measurement resolution / sensitivity.

[0027] Of course, the invention is not limited to these particular examples of device 2 and other kinds of electric, wireless or electronic devices may advantageously benefit from the integration of conductive pattern(s) 5 according to the invention with component 1. For example, as explained below, component 1 of the invention may be advantageously integrated into electric device 2 in which conductive pattern 5 forms a heating circuit, to form a particularly efficient electric heating system.

[0028] More advantageously, the roughness Sa of the top surface 5B of the conductive pattern 5 is at most 300 nm, preferably at most 200 nm, preferably at most 100 nm, preferably at most 50 nm, preferably at most 20 nm, more preferably at most 15 nm, such that the level of conduction losses at the top surface 5B of the conductive pattern 5 is particularly low and well controlled.

[0029] Advantageously, the upper surface 5B of the component 1 of the conductive pattern 5 further has a roughness Ra less than or equal to 500 nm, preferably less than or equal to 300 nm, preferably less than or equal to 200 nm, preferably less than or equal to 100 nm, preferably less than or equal to 50 nm, preferably less than or equal to 20 nm and even more preferably less than or equal to 15 nm.

[0030] Furthermore, for the reasons mentioned above, it is advantageous, in particular for wireless applications, for the underside 5A of the conductive pattern 5 to also have a very low roughness. Thus, the underside 5A of the conductive pattern 5 of the component 1 preferably has a roughness Sa of 500 nm or less. Further preferably, the roughness Sa of the underside 5A of the conductive pattern 5 is 300 nm or less, preferably 200 nm or less, preferably 100 nm or less, preferably 50 nm or less, preferably 20 nm or less, more preferably 15 nm or less. Advantageously, the underside 5A of the component 1 of the conductive pattern 5 further has a roughness Ra of 500 nm or less, preferably 300 nm or less, preferably 200 nm or less, preferably 100 nm or less, preferably 50 nm or less, preferably 20 nm or less, more preferably 15 nm or less.

[0031] Preferably, the thickness e of the conductive pattern 5 is greater than 10 nm, but is less than or equal to 400 nm, preferably less than or equal to 300 nm, more preferably less than or equal to 200 nm. Such a thinness of the conductive pattern 5 also helps that the component 1 is particularly space-saving and therefore easily integrable. Furthermore, by limiting the amount of metal contained in the component 1, it allows for a good control of the manufacturing costs as well as a reduction of the environmental impact of the component 1. Furthermore, due to the metal of the conductive pattern 5, such a thinness of the conductive pattern 5 can provide the conductive pattern 5 with a certain transparency within the range visible to the human eye.

[0032] According to a variant, the thickness e of the conductive pattern(s) 5 is substantially constant depending on the extent of the conductive pattern(s) 5, i.e. the thickness e is substantially the same at any point of the conductive pattern(s) 5 (FIGS. 1 and 2). As another variant, the component 1 can have several conductive patterns 5, the thickness e of each of which is substantially constant and differs from one conductive pattern 5 to another. As another variant, the thickness e of the conductive pattern(s) 5 is variable, i.e. the conductive pattern(s) 5 have at least a first region and a second region that are different from each other, and the thickness e of the conductive pattern(s) 5 increases or conversely decreases (thickness gradient) from said first region to said second region, nevertheless the value of the roughness Sa of the upper surface 5B of the conductive pattern(s) 5 is within the range of values ​​mentioned above. Such differences in thickness e of the conductive pattern(s) 5 within the above range of values ​​therefore advantageously make it possible to form conductive areas of different conductivity or resistivity, or likewise different transparency or reflection to electromagnetic waves, which may be particularly important for certain applications of the component 1 and the conductive pattern(s) 5 contained therein. For example, in the case of a component 1 of a wireless device, this makes it possible to create a change in the wave blocking / reflection properties of the metasurface. According to another example, in the case of the conductive pattern(s) 5 forming a heating circuit for an electric heating device, this makes it possible to generate areas of the heating circuit that provide different heating intensities when electricity is supplied to the heating circuit.

[0033] Advantageously, the metal of the conductive pattern 5 is selected from the group including silver (Ag), nickel (Ni), gold (Au), copper (Cu), aluminum (Al), iron (Fe) and tin (Sn), and alloys thereof. In particular, examples of nickel alloys include nickel-boron (Ni-B), nickel-phosphorus (Ni-P) or nickel-gold (Ni-Au) alloys. Even more advantageously, said conductive pattern 5 is formed of a (single) elemental metal, silver (Ag), taking into account the superior inherent electrical properties of silver (Ag) over other possible metals, apart from any non-metallic impurities.

[0034] Preferably, the metal of the conductive pattern 5 is more than 90%, preferably more than 95%, and even more preferably more than 98% pure. Thus, the conductive pattern 5 can advantageously be formed from silver Ag that is more than 90%, preferably more than 95%, and even more preferably more than 98% pure. Such a level of purity of the metal contributes in particular to the excellent electrical properties of the conductive pattern 5. Furthermore, if the component 1 is intended to be used in an electronic device forming a sensor and the conductive pattern 5 forms a sensor electrode, such a level of purity makes it possible to limit the risk of the presence of chemical element(s) that are potentially incompatible with sensitive sensor elements (electronic components, chemical detection substances, etc.) that may be placed in contact with the electrode formed by the conductive pattern 5. Thus, the risk of premature degradation or aging of the sensor is avoided.

[0035] Advantageously, the conductive pattern 5 of the component 1 is preferably 25.10 6 S / m (Siemens per meter) or higher, preferably 35.10 6 S / m or more, more preferably 45.10 6 It has a conductivity of S / m or more.

[0036] The conductive pattern 5 of the component 1 advantageously has a sheet resistance (Rs) of 800 mΩ / □ (ohms / square) or less, preferably 500 mΩ / □ (ohms / square) or less, preferably 300 mΩ / □ (ohms / square) or less, preferably 100 mΩ / □ (ohms / square) or less, preferably 40 mΩ / □ or less. The sheet resistance Rs can typically be measured by the four-point method, for example using a four-point measurement system PRO4 sold by MICROWORLD®. As is known, the four-point method makes it possible to characterize the resistivity of a thin metal film or layer at ambient temperature. The four-point method consists in contacting four aligned and equidistant electrodes (or "points") with the surface to be analyzed, two electrodes being used to inject a current of known value between two points on the surface, and two other electrodes being used to measure the induced potential difference. The combination of the above-mentioned low roughness Sa of the top surface 5B of the conductive pattern 5 with such a preferred value of the sheet resistance Rs makes it possible to further limit the conductive losses of the conductive pattern 5 and therefore provide the component 1 with even better performance. In practice, the value of the sheet resistance Rs of the conductive pattern 5 may depend on the thickness e of the conductive pattern 5. Thus, according to one example, the conductive pattern 5 of the component 1 is made of silver Ag, is more than 90%, preferably more than 95%, and even more preferably more than 98% pure, has a thickness e of 500 nm, and has a sheet resistance Rs of about 40 mΩ / □. According to another embodiment, the conductive pattern 5 is made of silver Ag, is more than 90%, preferably more than 95%, and even more preferably more than 98% pure, has a thickness e of 50 nm, and has a sheet resistance Rs of about 800 mΩ / □.

[0037] Preferably, said at least one conductive pattern 5 has a resolution of 100 μm or less, preferably 50 μm or less, preferably 20 μm or less, preferably 1 μm or less. Advantageously, the resolution of the conductive pattern 5 corresponds to the smallest width (e.g. smallest line width) of the conductive pattern 5 (considered in a plane parallel to the average extension plane of the dielectric surface 4) and / or the smallest distance (or spacing) between two conductive patterns 5 or between two parts of the same conductive pattern 5. Such precision of the definition of the conductive pattern(s) 5 of the component 1 further improves the electrical performance of the component 1. In particular, if the conductive pattern 5 of the component 1 forms a radio frequency antenna radiating element, such a resolution makes it possible to obtain a particularly high quality factor, which is favorable for the use of the component 1 in a radio frequency device 2 intended to operate in the range of radio frequencies from short wave (HF) to terahertz frequencies (THz). In particular, if the conductive pattern 5 of the component 1 forms a sensor electrode, the resolution of such a conductive pattern 5 contributes to a good measurement / detection precision. Thus, in other applications of component 1, for example where conductive pattern(s) 5 form a heating circuit for electric heating device 2, conductive pattern(s) 5 may have a particularly small width, limiting the effect of conductive pattern(s) 5 on the transparency of substrate 3. Typically, the resolution of conductive pattern 5 may be measured using a digital microscope, such as for example HIROX® Digital Microscope RH-2000.

[0038] Advantageously, according to the material and the electrical, radio or electronic application considered, the substrate 3 has a thickness between 8 μm and 15 mm, even more advantageously between 25 μm and 10 mm. In some cases, the intermediate coating 6 has a thickness preferentially between 5 nm and 100 μm, even more advantageously between 15 nm and 20 μm. These dimensional characteristics are advantageous for the component 1 to be particularly space-saving and therefore easily integrable, without compromising the performance of the component 1 in terms of electrical conductivity / resistivity.

[0039] According to the intended use of component 1, substrate 3 (and intermediate coating 6, if applied) may be transparent (e.g., in the wavelength range of the visible range of the human eye and / or in one or more specific electromagnetic wavelength range(s)) or, conversely, opaque. According to the intended use of component 1, substrate 3 (and intermediate coating 6, if applied) may be flexible, i.e., substrate 3 may be advantageously bent or folded solely by human force without breaking, deforming or irreversibly degrading. Such flexibility may advantageously aid the integrity of component 1. Alternatively, substrate 3 may, on the contrary, be substantially rigid, so that it cannot be bent or folded solely by human force without breaking, deforming or irreversibly degrading. Such flexibility may advantageously aid the robustness of component 1.

[0040] As a variant, the substrate 3 of the component 1, as well as the conductive pattern 5 preferably carried by the component 1, preferably have a three-dimensional shape. As used herein, "three-dimensional shape" advantageously means that the substrate 3 and the conductive pattern 5 form a physical object that extends in a substantially three-dimensional space along a non-negligible distance from each other. In other words, the substrate 3 of the component 1, as well as preferably the conductive pattern 5, is not flat, i.e. is not substantially two-dimensional, and has a very small thickness compared to its other two characteristic dimensions. The substrate 3 is therefore preferably a thermoformable substrate, i.e. its three-dimensional shape results from a step of thermoforming an initially flat thermoformable substrate.

[0041] Potentially, the substrate 3 of the component 1 can be overmolded, typically by injection molding, of a polymer material or a mixture of polymer materials, for example to form a protective and / or supporting structure for the substrate 3 carrying the conductive pattern 5, which advantageously contributes to the mechanical robustness of the component 1.

[0042] It is contemplated that the substrate 3, which may or may not have a three-dimensional shape, may be attached using any adhesive suitable for separate components that may form a protective and / or support structure for the substrate 3, as the case may be.

[0043] Preferably, component 1 comprises a top coating that is dielectric (i.e. non-conductive, electrically insulating) covering at least the top surface 5B of said at least one conductive pattern 5 carried by surface 3, so that said conductive pattern 5 is thus encapsulated between substrate 3 (or intermediate coating 6, if applied) and said top dielectric coating. The presence of such a top dielectric coating provides component 1 with a higher robustness and better reliability by protecting at least the conductive pattern 5 from external attack, in particular mechanical and / or chemical attack, or from accidental short circuits. For example, the top dielectric coating can be formed from a layer of protective varnish.

[0044] Optionally, component 1 comprises at least one electrical connection element 7 in electrical contact with conductive pattern(s) 5 carried by substrate 3 and attached to substrate 3, for example by bonding, soldering or crimping, for electrically connecting conductive pattern(s) 5 of component 1 to a remote organ or means separate from the component, suitable for electrical, wireless or electronic applications (e.g. electronic radio frequency communication modules, electronic signal processing circuits, power supply circuits, etc.). It is also conceivable that component 1 is designed and configured such that the electrical connection between conductive pattern(s) 5 of said separate remote organ or means can be made by direct surface contact with a reconnection using a metal blade connector / EMC joint.

[0045] As introduced above, the present invention also relates to an electric, wireless or electronic device 2 comprising a component 1 according to the invention, as described above. It is therefore an electric, wireless or electronic device 2 comprising a component 1 comprising a substrate 3 provided with a dielectric surface 4 carrying at least one conductive pattern 5, said conductive pattern 5 having a lower surface 5A in contact with said dielectric surface 4 and an opposite upper surface 5B, said component 1 being a component 1 according to the above described component 1 according to the invention. The above description of the component 1 according to the invention therefore applies mutatis mutandis to the electric, wireless or electronic device 2 according to the invention.

[0046] Indeed, as already mentioned above, the present invention is not particularly limited with respect to the nature of the electrical, wireless or electronic device 2. Nevertheless, several types of electrical, wireless or electronic devices 2 have been identified that can advantageously benefit from the integration of a component 1 according to the present invention.

[0047] In particular, according to one embodiment, device 2 constitutes a wireless device, and conductive pattern 5 of component 1 forms a radio frequency antenna radiating element, i.e. an antenna portion (sometimes simply referred to as an "antenna") capable of transmitting and receiving radio waves.

[0048] In accordance with what has been described above in relation to the component 1 according to the present invention, the substrate 3 and the conductive pattern(s) 5 of the component 1 of such a wireless device 2 may advantageously have a three-dimensional shape, which may make it easier to integrate the component 1 within the wireless device 2.

[0049] Said wireless device 2 may comprise an electronic chip 8 attached to the substrate 3 of the component 1 in electrical contact with the conductive pattern 5 carried by the component 1, for example when the wireless device 2 constitutes or comprises an RFID tag. Alternatively, the wireless device 3 may not comprise such an electronic chip, but may comprise a radio frequency electronic communication module separate from and remote from the component 1, connected to the conductive pattern(s) 5 of the component 1 by an electrical connection element 7 attached to the substrate 3 in electrical contact with the conductive pattern(s) 5 and a suitable connection cable 9 connecting the electronic communication module to the electrical connection element 7. For example, the electrical connection element 7 attached to the substrate 3 may be a male or female radio frequency RF connector of the SMA type ("SubMiniature version A"), or a male or female radio frequency RF connector of the U.FL or W.FL type, manufactured by HIROSE®. Potentially, the wireless device 2 may further comprise a radio frequency transmitter and / or receiver (not shown) designed and configured to remotely interact at radio frequencies with a radio frequency antenna radiating element (and / or possibly electronic chip 8) of the wireless device 2 to establish a wireless connection for information transmission between the wireless device 2 and the radio frequency transmitter and / or receiver.

[0050] FIG. 3 shows in particular a wireless device 2 constituting a three-dimensional tag for a UHF radio frequency identification ("Radio Frequency IDentification" (RFID)) system, with a conductive pattern 5 forming an RFID radio frequency antenna radiating element. The substrate 3 of the component 1 consists of a polycarbonate (PC) sheet with an initial thickness of 250 μm, thermoformed as a hemisphere ("cup"). The wireless device 2 comprises an RFID electronic chip 8, here an RFID Monza R6 chip marketed by IMPINJ®, attached to the substrate 3 using an adhesive, in electrical contact with two adjacent contact areas of the conductive pattern 5. A conductive pattern 5 made of pure silver Ag is glued to the surface of the substrate 3, following the three-dimensional hemispherical shape of the substrate 3. The thickness e of the conductive pattern 5 is of the order of 300 nm. The top surface 5B of the conductive pattern 5 has a roughness Sa of about 20 nm. The conductive pattern 5 has a sheet resistance Rs of about 85 mOhm / □.

[0051] FIG. 4 shows an example of a component 1 of a wireless device 2, whose conductive pattern 5 forms a WiFi® (2.4 GHz) dipole radio frequency antenna radiating element, for example for use in the field of the Internet of Things (IoT). Here, the conductive pattern 5 defines two radiative half strands and a two-wire power line. The substrate 3 of the component 1 consists of a polycarbonate (PC) sheet with an initial thickness of 250 μm, thermoformed as a hemisphere. The thickness e of the conductive pattern 5 is of the order of 300 nm. The top surface 5B of the conductive pattern 5 has a roughness Sa of about 20 nm. The conductive pattern 5 has a sheet resistance Rs of about 85 mOhm / □. To enable interconnection with a radio frequency electronic communication module (not shown), an electrical connection element 7, such as a HIROSE® U.FL RF connector, is glued to the substrate 3 in contact with the two-wire line of the antenna radiating element using the isotropic conductive adhesive PANACOL Elecolit® 3661. An end of a suitable radio frequency coaxial cable 9 is connected to the electrical connection element 7, the other end of the cable 9 being intended to be connected to an electronic radio frequency communication module.

[0052] According to another embodiment, the device 2 forms a sensor (or detector) as an electronic device 2, and the aforementioned at least one conductive pattern 5 of the component 1 then forms an electrode of the at least one sensor or detector. Possibly, a chemical detection substance may be present on at least a part of the upper surface 5B of the conductive pattern 5 (chemical sensor). The device 2 may advantageously comprise an adapted electronic measurement circuit connected to the conductive pattern 5.

[0053] As an example, the conductive pattern 5 may form a capacitive sensor electrode (or "capacitive electrode") for detecting a touch applied to the component 1 by a user's finger or the presence of a substance on the component 1 (e.g. liquid water or frost), for example, by measuring one of the capacitances of the conductive pattern 5. FIG. 5 shows an example of such a component 1, whose conductive pattern 5 forms a capacitive sensor electrode. In this example, the substrate 3 consists of a sheet of polyethylene terephthalate (PET) with an initial thickness of 125 μm. The conductive pattern 5 consists of pure silver Ag with a thickness e of about 250 nm. The top surface 5B of the conductive pattern 5 has a roughness Sa of about 20 nm. The conductive pattern 5 has a sheet resistance Rs of about 105 mOhm / □.

[0054] According to another example (not shown), the conductive pattern(s) 5 may form a resistive sensor electrode (or "resistive electrode"), for example to detect the deformation of the substrate 3 (deformation gauge) by measuring the change in electrical resistance between two distinct points (and typically between the two opposite ends) of the conductive pattern 5. It may also make it possible to indirectly measure the temperature of the substrate 3, if the latter is made of a material with a relatively high coefficient of thermal expansion. According to yet another example (not shown), the component 1 may include one or more conductive pattern(s) 5 forming two electrodes, between which a sensitive element is placed whose resistive properties may vary as a function of environmental conditions (concentration of a particular gas in the surrounding atmosphere, humidity, temperature, etc.).

[0055] Moreover, as introduced above, it has been observed that the component 1 according to the invention can find application in a very interesting way in an electric device, an electric heating device 2, in which the conductive pattern 5 of the component 1 forms a heating circuit (typically when a current is applied between the two ends of the conductive pattern 5). Typically, the heating circuit (or "resistance circuit") can take the form of one or more wire(s), one or more grid(s) and / or one or more conductive coil(s). Advantageously, the component 1 can comprise two electrical connection elements 7, for example two omnibus bars, attached to the substrate 3 in electrical contact with the conductive pattern(s) 5. The electric heating device 2 can advantageously comprise a control and power circuit connected to the aforementioned electrical connection elements 7.

[0056] As an example, FIG. 6 shows an electric heating device 2 forming a heating / de-icing radome for a radio tracking system (proximity radar sensor) with a radar sensor module XM132 from ACCONEER operating at 60 GHz. The component 1 of the electric heating device 2 comprises a substrate 3 made of a thermoformed polycarbonate (PC) sheet with an initial thickness of 250 μm. A conductive pattern 5 made of pure silver Ag forms a grid. To ensure the transparency of the radome to the radar waves of the radar sensor module, the grid has a mesh with a width of 200 μm and an opening of 5,000 μm. The conductive pattern 5 has a thickness e of 120 nm. The top surface 5B of the conductive pattern 5 has a roughness Sa of about 20 nm. The conductive pattern 5 has a sheet resistance Rs of about 250 mOhm / □. When the conductive pattern 5 is connected to a DC control and power circuit (voltage about 25 V, current about 1.4 A), it has a surface roughness of 0.05 m. 2 35 W (i.e., 600 W / m 2 ) and can reach a surface temperature of component 1 of over 60° C. after 1 minute of heating.

[0057] The different steps of the method for manufacturing a component 1 according to the invention are now described by way of illustrative and non-limiting example. According to this method, metallic conductive pattern(s) 5 are manufactured by selective metallization of a previously masked substrate, according to the technique of electroless chemical deposition of metal on the substrate surface by spraying, in the form of one or more aerosol(s), one or more metallization solution(s) containing at least one metal in metal cation form (oxidizing agent) and at least one reducing agent capable of converting the metal cation into a metal.

[0058] This method advantageously makes it possible to obtain a component 1 according to the invention in a particularly simple, fast and efficient manner. The example of a component 1 described above in relation to figures 3 to 6 was obtained using such a method. Step A: Providing a Substrate

[0059] Advantageously, the material selected for the substrate 3 is a dielectric material, preferably a polymer material or a composite polymer-matrix material. In order to obtain a component 1 in which the substrate 3 has a three-dimensional shape, the substrate is preferably initially in a flat shape (flat substrate), typically with a thickness between 8 μm and 15 mm, and the material of the substrate 3 is selected so that it is thermoformable. Possible thermoformable polymer materials include, as non-limiting examples, polystyrene (PS), impact polystyrene (SB / HIPS), polyethylene (PE), polypropylene (PP), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), or polylactic acid (PLA), thermoplastic polyesters such as polyethylene terephthalate (PET) and glycolated polyethylene terephthalate (PETG). In order to obtain a component 1 in which the substrate 3 is substantially flat, the material of the substrate 3 can advantageously be selected from among the thermoformable polymer materials listed above or from among the examples of thermosetting polymer materials of polyimide, thermosetting polyester, phenolic resin, and epoxy.

[0060] It is further advantageous in terms of the ease with which the above-mentioned level of roughness Sa of the conductive pattern(s) 5 can be obtained, the selected substrate 3 itself having an upper surface intended to carry the conductive pattern 5 and having a roughness Sa of less than or equal to 500 nm, preferably less than or equal to 300 nm, preferably less than or equal to 200 nm, preferably less than or equal to 100 nm, preferably less than or equal to 50 nm, preferably less than or equal to 20 nm and even more preferably less than or equal to 15 nm. Potential Step B: Providing a Substrate Surface

[0061] The method may include a step B of preparing the substrate surface to facilitate and / or increase the efficiency of the implementation of the following steps of the method. Step B may include an operation of cleaning and / or degreasing the substrate surface by any known suitable product. In addition to or instead of such a cleaning / degreasing operation, step B may include an operation of depositing an intermediate coating 6 made of a dielectric material, such as a layer of varnish, for example a UV crosslinked varnish applied by spraying, on the substrate surface, by any known suitable means, such as a compressed air spray gun (for example a High Volume Low Pressure (HVLP) spray gun). In this case, the upper surface of the intermediate coating 6 forms the dielectric surface 4, on which the substrate 3 is provided. The implementation of such an intermediate coating 6 may, in some cases, make it possible to "smooth" the surface underlying the substrate 3, thereby providing the dielectric surface 4 with a roughness Sa of 500 nm or less, preferably 300 nm or less, preferably 200 nm or less, preferably 100 nm or less, preferably 50 nm or less, preferably 20 nm or less, even more preferably 15 nm or less. Alternatively or supplementarily, step B may comprise a physical and / or chemical treatment to reduce the roughness Sa of the surface of the substrate 3, for example by sandblasting or shot blasting, so as to reach the preferred value ranges mentioned above. Step C: Applying a Temporary Masking Coating

[0062] In order to allow selective metallization of the substrate 3 making it possible to obtain the desired metallic conductive pattern(s), the method comprises the act of forming a temporary masking coating which adheres to a dielectric surface 4 provided on the substrate 3 in order to obtain a masked substrate having at least one unmasked area and thus selectively defining one or more specific area(s) of the dielectric surface 4 carrying the conductive pattern(s) 5.

[0063] Advantageously, step C is carried out by selective or non-selective deposition, followed by selective removal / elimination, of a layer of a liquid or pasty masking composition on the dielectric surface 4 of the substrate 3. After depositing the masking composition, potentially the deposited masking composition may be dried and / or cured. Depending on the formulation of the selected masking composition, the drying and / or curing of the masking composition may comprise, possibly, drying / desolvation under the effect of heat input, or polymerization / crosslinking of the deposited masking composition under the effect of heat input and / or under the action of actinic radiation (e.g. by exposure to ultraviolet (UV) light). The deposition of the masking composition layer may be carried out selectively on the flat substrate surface by any known suitable application technique, for example screen printing, pad printing, flexographic printing, rotogravure printing and / or direct printing (e.g. droplet or "inkjet"), making it possible to achieve a resolution of less than 20 μm for the conductive pattern(s) 5. Alternatively, the formation of a temporary masking coating by photolithography, for example from the aforementioned masking composition, may make it possible to obtain a resolution of less than 1 μm, typically of the order of 100 nm, for the conductive pattern(s) 5. Optional Thermoforming Step D

[0064] In order to obtain a component 1 in which the substrate 3 has a three-dimensional shape, as mentioned above, it is preferred that the material of the substrate 3 is chosen to be thermoformable and that the substrate 3 is thus initially in a flat form (flat substrate). In this case, the method then advantageously comprises a step D of thermoforming the mask substrate obtained at the end of the step D of forming the temporary masking coating.

[0065] Step D of thermoforming the masked substrate can advantageously be carried out by any known thermoforming means and techniques, obviously adapted to the substrate properties (nature of the thermoforming material, thickness of the substrate, etc.) and possibly to the inherent properties of the temporary masking coating. Typically, step D is carried out by conduction and / or convection and / or radiation, advantageously by heating the flat substrate uniformly, until the thermoforming material of the substrate is heated at a forming temperature sufficient to make the flat substrate malleable. The forming temperature in question can obviously vary depending on the thermoforming material selected. In the case of thermoformable polymeric materials, the forming temperature is typically chosen at least equal to the glass transition temperature of the material considered, nevertheless advantageously lower than the melting temperature of the material in question. Once made malleable, the flat substrate is pressed (or counterformed), advantageously by vacuum and / or pressure suction, against a male ("positive") or female ("negative") mold, so that the flat substrate is deformed and adapted to the mold shape. The deformed substrate is then cooled until the thermoforming material hardens and retains the shape imparted by the mold, after which the deformed substrate is removed from the mold.

[0066] Since the substrate and the temporary masking coating are thermoformed (or thermodeformed) simultaneously during thermoforming step D, it is desirable that the temporary masking coating is itself advantageously thermoformable, or at least thermodeformable, so that it can be elongated and thus follow the deformations of the substrate whilst adhering to the surface of the substrate during thermoforming step D. The temporary masking coating is therefore advantageously designed such that it can be subjected to the conditions for carrying out step D of thermoforming the substrate without significant degradation of its function of masking the surface of the substrate, particularly in terms of its ability to be elongated / deformed without breaking.

[0067] In order to ensure perfect control of the shape of said conductive pattern 5 desired to be obtained on the surface of the thermoformed substrate, it is advantageous to provide, before the above-mentioned step C, a step E of modelling the deformations of the substrate and the temporary masking coating during the thermoforming step D, and of defining (or modelling) said at least one conductive pattern 5 to be obtained, thereby defining a two-dimensional masking pattern along which a temporary masking coating is then formed on the surface of the substrate in the above-mentioned temporary masking coating formation step C. In other words, the definition of the two-dimensional masking pattern is performed by "reverse anamorphosis", along which a temporary masking coating is formed on the substrate surface in step C, making it possible to obtain the desired conductive pattern(s) 5 by predicting and compensating for the effects of the deformations generated by the thermoforming step D. Such a step of defining a two-dimensional masking pattern can be carried out using commercially available computer software, such as the software T-SIM® by SIMCON (formerly CADFLOW), the software PAM-FORM™ by ESI GROUP, the software solution ANAMAP™ by KALLISTO or the software Thermo 3D™ by QUADRAXIS. Step F: Increasing the energy of the dielectric surface

[0068] The method preferably comprises a step F of increasing the surface energy of the dielectric surface 4 of the substrate 3 to a value of at least 50 dynes or 55 dynes, preferably at least 60 dynes or 65 dynes, or even more preferentially at least 70 dynes, to ensure that the substrate is sufficiently wetted for the metallization and that the obtained metal deposits obtained after the metallization and intended to form the conductive pattern(s) 5 adhere sufficiently. Step F may be carried out before or after step C of forming the temporary masking coating.

[0069] The treatment step F for increasing the energy of the substrate surface comprises: A physical treatment, preferably selected from the physical treatments flaming, plasma treatment, corona treatment and combinations thereof; and / or Preferably, a chemical treatment selected from the following chemical treatments: application of a silane-based solution, surface depassivation using one or more acid solution(s), rare earth oxide polishing, fluorination, acid or alkali chemical attack to create micro-roughness, and combinations thereof. This can be carried out by:

[0070] More preferentially, the physical treatment is a flaming and / or a plasma treatment, especially when the flexible or rigid substrate is made of a thermoforming polymer material or a composite polymer-matrix thermoforming material. The flaming operation consists, for example, in passing the substrate under a flame, the temperature of which is, for example, between 1,200°C and 1,700°C. The flaming duration is generally between 4 and 50 seconds. The plasma treatment corresponds, for example, to the passage of the substrate to be metallized in a plasma torch. For example, the substrate may be exposed for 2 minutes to a so-called "air" plasma, 80% nitrogen / 20% oxygen at 0.5 mbar (i.e. 50 Pa). More preferentially, the chemical treatment is a fluorination treatment, especially when the flexible or rigid substrate is made of a thermoforming polymer material or a composite polymer-matrix thermoforming material. The fluorination corresponds, for example, to contacting the substrate to be metallized with a gaseous solution based on an inert gas (argon) containing a fluorine additive, in an enclosure under reduced pressure. Step G: Wetting the Dielectric Surface

[0071] The method may comprise, after the treatment step F for increasing the surface energy, a step G of wetting the dielectric surface 4, which usually consists of coating the dielectric surface 4 with a liquid film, for example by spraying or evaporation / condensation of the wetting liquid, in order to facilitate the subsequent spreading of the metallization solution(s) ("redox solution(s)"). The wetting liquid is preferably selected in the group of deionized or non-deionized water, optionally with the addition of one or more anionic, cationic or neutral surfactant(s), alcoholic solutions containing one or more alcohol(s) (for example isopropanol, ethanol and mixtures thereof), and mixtures thereof. For example, deionized water with the addition of an anionic surfactant and ethanol can be selected as the wetting solution. The wetting duration depends on the dielectric surface 4 considered and on the spraying or evaporation / condensation rate of the wetting liquid. Step H: Activating / sensitizing the dielectric surface

[0072] Within the framework of metallization by electroless deposition by spraying one or more metallization solutions(s) in the form of an aerosol, a previous activation (or at least "sensitization") step H may be necessary to deposit certain metals, particularly with the aim of promoting a redox metallization reaction. During step H, the substrate surface is brought into contact with at least one chemical sensitizing species, which is adsorbed on the surface of the substrate 3 and subsequently promotes the metallization reaction.

[0073] Preferably, the activation step H is carried out after the temporary masking coating formation step C, so that the chemical sensitizing species or species are adsorbed to both the temporary masking coating and to the unmasked, i.e. uncovered, area(s).

[0074] In practice, step H is preferably carried out by spraying the at least one sensitizing solution onto the substrate surface, and by any known suitable means, such as, for example, using a compressed air paint gun (e.g., a high volume, low pressure (HVLP) spray gun). Alternatively, step H can be carried out by immersing the substrate in the at least one sensitizing solution.

[0075] A first sensitizing solution, for example based on stannous chloride (SnCl2) or SnSO4 / H2SO4 / quinol / alcohol, is applied by spraying or immersion. The ions Sn 2+ Palladium or silver based solutions, or PdSn colloidal solutions formed elsewhere, capable of reacting with the nucleation centers on the surface of the substrate, are then deposited in the same way. More precisely, reference can be made, for example, to "Metal Finishing Guidebook and Directory Issue", 1996 Metal Finishing publication, pages 354, 356 and 357. H. Narcus, "Metallizing of Plastics", Reinhold Publishing Corporation, 1960, Chapter 2, page 21. F. Lowenheim, or also to "Modern electroplating", John Wiley & Sons publication, 1974, Chapter 28, page 636. Advantageously, the substrate surface sensitization is carried out using a stannous chloride based sensitizing solution, for example according to the embodiment described in document FR-2 763 962 B1. In this case, there is no intermediate step, but a rinsing step with a rinsing liquid is carried out immediately after the sensitization. As a variant, surface activation of the substrate 3 is carried out using a sensitizing solution, for example according to the embodiment described in document FR-2 763 962 B1, in which case the activation step H is immediately followed, without intermediate steps, by a rinsing step with a rinsing liquid as indicated in the examples below. Electroless Chemical Deposition Metallization Step I

[0076] The method then comprises a metallization step I for forming metal deposits intended to form metallic conductive pattern(s) 5, this step I comprising: a single metallization solution comprising said at least one metal in metal cation form and said at least one reducing agent adapted to convert the metal cations to metal; or two different solutions, a first solution ("oxidizing solution") containing at least one metal in the form of a metal cation (oxidizing agent(s)) and a second solution ("reducing solution") containing one or more reducing agent(s); Or similarly, by electroless chemical deposition using multiple separate solutions, each of which may contain either at least one metal in metal cation form (oxidizing agent(s)) or one or more reducing agent(s), provided that at least one of the solutions (the "oxidizing solution") contains at least one metal in metal cation form and at least another one of the solutions (the "reducing solution") contains one or more reducing agent(s).

[0077] The reducing agent is advantageously selected to be strong enough to reduce the metal cation to the metal, i.e. the selected standard redox potential of the reducing agent's oxidizing / reducing couple is lower than the standard redox potential of the oxidizing agent's oxidizing / reducing couple (Gamma rule). Such electroless modification is particularly advantageous in that it allows the formation of solid metal deposits as contemplated hereinabove on the surface of substrates, whether conductive or not, independently, and furthermore with thicknesses advantageously included in the range of values ​​indicated above.

[0078] During the metallization step I, the metallization solution(s) is / are sprayed in the form of one or more aerosol(s) onto the masked substrate, in particular at least onto the unmasked area(s) of the masked substrate. As used herein, "aerosol" means a set of fine particles of the metallization solution(s) suspended in a gaseous medium (for example air). It may therefore advantageously be a mist of droplets of less than 100 μm, preferably less than 60 μm, more preferentially also between 0.1 μm and 50 μm, obtained by atomization and / or atomization of the metallization solution(s).

[0079] Advantageously, the metallization solution(s) ("redox solution") can be obtained from a solution, advantageously an aqueous solution, of one or more oxidized metal cation(s) (usually obtained by dissolving one or more corresponding metal salt(s)) and one or more reducing component(s), preferably by dilution of a concentrated stock solution, the diluent being preferably demineralized water. Depending on the nature of the metal deposit to be formed, the spraying of the metal solution can be carried out continuously, i.e. all at once, or discontinuously by alternating spraying phases and relaxation periods. For example, in the case of silver-based metal deposits, the spraying is preferentially carried out continuously. For example, in the case of nickel-based metal deposits, the spraying is preferentially carried out discontinuously by alternating spraying phases and relaxation periods. Depending on the thickness of the desired metal deposit, the spraying duration can advantageously be in the range of 1 dm 2 This may vary between 0.5 and 200 seconds, preferably between 1 and 50 seconds and even more preferentially between 2 and 30 seconds for the substrate surface area to be metallized.

[0080] Spraying of the metallization solution(s) can be carried out using any suitable spraying means, preferably using one or more compressed air spray gun(s), for example one or more high volume low pressure (HVLP) spray gun(s).

[0081] According to the first spraying method, one or more metal cation solution(s) ("oxidizing solution(s)") and one or more reducing agent solution(s) ("reducing solution(s)") are simultaneously and continuously sprayed in the form of one or more aerosol(s) onto the surface to be treated. In this case, the mixing of the oxidizing and reducing solutions may be performed immediately before forming the aerosol, or similarly, by fusing the aerosol generated from the oxidizing and reducing solutions, preferably before contacting the substrate surface. According to the second spraying method, one or more metal cation solutions ("oxidizing solution(s)") and then one or more reducing agent solutions ("reducing solution(s)") are sprayed successively using one or more aerosol(s). In other words, the spraying of the redox solution is carried out by separate alternating spraying of one or more solutions of one or more metal oxidizing agents and one or more solutions of one or more reducing agents. According to the third spraying method, the aforementioned at least one metal in metal cation form ("oxidizing agent(s)") and the aforementioned at least one The metastable metallization solution, including the mixture with the reducing agent, is sprayed in aerosol form and then, after spraying onto the substrate surface, the metallization solution is activated to cause the conversion of the metallization cation(s) to metal, preferably by contact with a primer, advantageously added using one or more aerosol(s) before, during and after spraying of the metallization solution. Priming or activation of the redox reaction is then possibly obtained by any suitable physical (temperature, UV, etc.) or chemical means.

[0082] Preferably, water is chosen as the solvent for preparing the metallization solution(s) to be sprayed as aerosol(s). The concentration(s) of the metal salt(s) of the sprayed oxidation solution(s) is preferentially between 0.1 g / l and 100 g / l, more preferably between 1 g / l and 60 g / l. In some cases, the concentration(s) of the metal salt(s) of the stock solution(s) is preferably between 0.5 g / l and 500 g / l, or the dilution factor of the stock solution(s) is preferably between 5 and 5,000. Advantageously, according to the nature of the metal of the conductive pattern 5 to be obtained, the metal salt is chosen among silver nitrate, nickel sulfate, copper sulfate, tin chloride, aurochloride acid, iron chloride, cobalt chloride, and mixtures thereof. The reducing agent(s) is / are preferably selected from among borohydride, dimethylaminoborane, hydrazine, sodium hypophosphite, formaldehyde, lithium aluminum hydride, reducing sugars such as glucose derivatives or sodium erythorbate, and components of mixtures thereof. The concentration(s) in the metal salt(s) of the reducing solution(s) to be sprayed is / are preferentially between 0.1 g / l and 100 g / l, more preferably between 1 g / l and 60 g / l. In some cases, the concentration(s) of the reducing agent(s) in the stock solution(s) is / are preferably between 0.5 g / l and 250 g / l, or the dilution factor of the stock solution(s) is / are preferably between 5 and 2,500.

[0083] For example, a conductive pattern 5 made of pure silver Ag can be obtained by simultaneous spraying in aerosol form (first spraying method) of a first aqueous metallization solution (oxidizing solution) based on silver nitrate at a concentration of 2 g / l and having a pH>9, and a second metallization solution (reducing solution) based on glucose, for 80 seconds, by means of an HVLP gun set at a spraying pressure of less than 2.5 bar (i.e. 2.5 Pa). Step J of removing the temporary masking coating

[0084] The method further comprises a step J of removing the temporary masking coating, the purpose of which is to remove the temporary masking coating present on the substrate 3 and any latent metal deposits that may have formed on the temporary masking coating at the end of the metallization step I, thus "revealing" the metal conductive pattern 5.

[0085] Advantageously, step J is carried out at least partly by chemical, non-mechanical means in order to remove said temporary masking coating in a simple and clean way by limiting the risk of reducing the fineness and precision of the conductive pattern(s) 5 to be obtained. Advantageously, the temporary masking coating removal step J is carried out during the metallization step I, or at least partly during and after step I, or at least partly during and after step I and partly before step I. As such, the temporary masking coating removal step J comprises (or even essentially consists of) at least one operation of (at least partly) dissolving the temporary masking coating using the metallization solution implemented during the metallization step I or at least one solvent contained in one of the metallization solutions. By "dissolving with at least one solvent" herein is meant the total or partial disintegration, decomposition, or loss of bond of the temporary masking coating under the action of a particular fluid (preferably a liquid) selected for its particular chemical aggressiveness towards the temporary masking coating, as well as allowing the temporary masking coating to disintegrate, detach, desorb, and be expelled from the substrate surface. It may therefore be, but is not necessarily, a mechanism for dissolving in a solvent in the strict chemical sense.

[0086] Preferably, said temporary masking coating is alkali-soluble (or at least alkali-sensitive) so that it can be preferentially dissolved by the alkaline solvent contained in the metallization solution or one of the metallization solutions carried out in step I. In practice, the selected metallization solution(s) has a highly alkaline pH (usually higher than 9), so that the metallization solution(s) can dissolve the temporary masking coating during the metallization step I. For example, during spraying of the metallization solution(s) in the form of aerosol(s), the unmasked areas of the substrate are metallized, while the temporary masking coating is dissolved and expelled by the effluent, revealing the desired metallic conductive pattern(s).

[0087] Step J may optionally include, prior to said dissolving operation of the temporary masking coating, an exposure operation under actinic radiation (e.g. under UV light) and / or a heat treatment operation on the temporary masking coating in order to weaken it and / or make it easier to partially dissolve it. Step J may optionally include, after such dissolving operation, an operation consisting in particular of promoting the evacuation of the dissolved temporary masking coating and / or any debris that is not completely dissolved from the temporary masking coating by conveying it in the liquid phase and / or by mechanically conveying it. Steps K and L of rinsing and drying the surface of the metallized substrate

[0088] After the metallization step I, the method preferably comprises a step K of rinsing the surface of the metallized substrate in order to expel residues from the temporary masking coating. The rinsing step K may be carried out, for example, by spraying / jetting one or more rinsing liquid(s) using an HVLP gun or by soaking / immersion in one or more rinsing liquid(s). Optionally, to continue with the temporary masking coating removal step J, the rinsing liquid is preferably water, more preferably demineralized water, except in cases where the rinsing liquid(s) (or one of them) contains or forms a solvent (other than water) for dissolving the temporary masking coating. In particular, after a first rinsing by water spray, a complementary rinsing can be carried out by immersion in a bath or by spraying with a solution containing a solvent of the ethanol / isopropanol type, ensuring the complete absence of residues of the temporary masking coating and the metal deposits carried by these temporary masking coatings.

[0089] Step K of rinsing the metal substrate surface can be followed by a step L of drying the metallized substrate surface and draining the rinsing liquid. Such drying is typically carried out at ambient temperature, for example at 5 bar (i.e. 5.10 5 This can be done by blowing a stream of compressed air at a pressure of 100 MPa (200 psi) or by using an air knife type blowing system. Optional Step M of Finishing the Metallized Substrate Surface

[0090] Advantageously, a step M of finishing treatment of the metallized substrate surface may be provided, consisting of the formation of a top dielectric coating (protective coating) as described herein above, covering at least the upper surface 5B of said at least one conductive pattern 5 carried by the surface 3. Such a finishing step may typically be achieved by depositing / applying, by any known suitable technique, at least one finishing layer of a curable and / or crosslinkable liquid composition (for example by exposure to UV or thermal curing) on ​​the surface of the substrate carrying the conductive pattern(s) 5. The liquid composition may for example be a paint or varnish, advantageously chosen from the group of alkyd, polyurethane, epoxy, vinyl, acrylic and mixtures thereof. Preferably, the liquid composition is a varnish, potentially pigmented / pigmented, advantageously chosen from the group of: epoxy, alkyd and acrylic compositions. Optional step N of assembling additional elements

[0091] Optionally, the method may include a step N of assembling one or more additional elements, such as electric or electronic components, e.g. electronic chips 8 and electrical connection elements 7, on the substrate 3 provided with one or more metallic conductive patterns 5. Advantageously, such an assembly step N may be carried out using one or more robotized surface mounted component (SMD) placement systems, commonly known as "pick and place" or "P&P" machines, one or more robotized arms. Such an assembly step may advantageously be carried out by soldering and / or using an isotropic or anisotropic conductive adhesive, for example in the form of a film or paste and of any suitable chemistry (silicone, epoxy, acrylic, etc.). The conductive adhesive may be cured if necessary. [Industrial Applicability]

[0092] The invention finds its application in the field of design and manufacture of components for electrical, wireless or electronic devices, such as in particular for radio frequency transmitter and / or receiver wireless devices or for sensors / detectors, comprising a substrate with a dielectric surface carrying at least one conductive pattern.

Claims

1. A component (1) for an electric, wireless or electronic device (2) comprising a substrate (3) provided with a dielectric surface (4) carrying at least one conductive pattern (5), the conductive pattern (5) having a lower surface (5A) in contact with the dielectric surface (4) and an opposite upper surface (5B), characterized in that the conductive pattern (5) is formed of metal, the upper surface (5B) of the conductive pattern (5) has a roughness Sa of 500 nm or less, and the conductive pattern (5) has a thickness (e) of 10 nm to 500 nm and a sheet resistance of 800 mΩ / □ or less.

2. 2. The component (1) according to claim 1, characterized in that the roughness Sa of the top surface (5B) of the conductive pattern (5) is less than or equal to 300 nm, preferably less than or equal to 200 nm, preferably less than or equal to 100 nm, preferably less than or equal to 50 nm, preferably less than or equal to 20 nm, further preferably less than or equal to 15 nm.

3. 3. Component (1) according to claim 1 or 2, characterized in that the lower surface (5A) of the conductive pattern (5) has a roughness Sa of less than or equal to 500 nm.

4. 4. The component (1) according to claim 3, characterized in that the roughness Sa of the lower surface (5A) of the conductive pattern (5) is less than or equal to 300 nm, preferably less than or equal to 200 nm, preferably less than or equal to 100 nm, preferably less than or equal to 50 nm, preferably less than or equal to 20 nm, further preferably less than or equal to 15 nm.

5. 5. Component (1) according to any one of the preceding claims, characterized in that the thickness (e) of the conductive pattern (5) is less than or equal to 400 nm, preferably less than or equal to 300 nm, and more preferably less than or equal to 200 nm.

6. Component (1) according to any one of claims 1 to 5, characterized in that the metal is selected from the group comprising silver (Ag), nickel (Ni), gold (Au), copper (Cu), aluminium (Al), iron (Fe) and tin (Sn), and alloys thereof.

7. Component (1) according to claim 6, characterized in that the conductive pattern (5) is made of elemental metal, silver (Ag).

8. 8. Component (1) according to any one of the preceding claims, characterized in that the metal of the conductive pattern (5) is more than 90%, preferably more than 95%, and even more preferably more than 98% pure.

9. 9. Component (1) according to any one of the preceding claims, characterized in that the conductive pattern (5) has a sheet resistance of less than or equal to 100 mΩ / sq, more preferably less than or equal to 40 mΩ / sq.

10. Component (1) according to any one of the preceding claims, characterized in that the conductive pattern (5) has a resolution of 100 μm or less, preferably 20 μm or less, preferably 1 μm or less.

11. Component (1) according to any one of claims 1 to 10, characterized in that it comprises at least one electrical connection element (7) attached to the substrate (3) in electrical contact with the conductive pattern (5).

12. Component (1) according to any one of the preceding claims, characterized in that the substrate (3) is made of a polymer material, a composite polymer matrix material, paper, glass, textiles, leather or a ceramic material.

13. Component (1) according to any one of claims 1 to 12, characterized in that the surface of the substrate (3) is covered with an intermediate coating (6) forming the dielectric surface (4) on which the conductive pattern (5) is provided.

14. Component (1) according to any one of claims 1 to 13, characterized in that the substrate (3) and the conductive pattern (5) have a three-dimensional shape, the substrate (3) being preferably a thermoformed substrate.

15. 15. An electric, radio or electronic device (2) comprising a component (1) according to any one of claims 1 to 14.

16. 16. The device (2) according to claim 15, constituting a wireless device, characterized in that said conductive pattern (5) forms a radio frequency antenna radiating element.

17. 16. The device (2) according to claim 15, characterised in that it constitutes a sensor and the conductive pattern (5) forms a sensor electrode, for example a capacitive or resistive sensor electrode.

Images