Manufacturing procedure for an electric current sensor using additive manufacturing

Abstract

The invention relates to a method for manufacturing an electric current sensor (SHE) comprising the following steps: a) providing a substrate (SBT) made of metal or metal alloy, b) making a non-through cavity (CVT) in said substrate such that said cavity separates the substrate into two zones (Z1, Z2), c) making, by additive manufacturing, a resistive element (ER) in said cavity (CVT), d) annealing the assembly thus obtained, e) removing a part of the substrate (SBT) to leave only the resistive element (ER) between the two zones (Z1, Z2) of the substrate, and f) defining, within each zone (Z1, Z2), a connection terminal (BCE1, BCE2) to obtain electrodes (PEL, DEL).

Description

Domaine technique de l'invention

[0001] The invention relates to the field of manufacturing electric current sensors, for example an electric shunt. Arrière-plan technique

[0002] A known electrical shunt is shown on the figure 1 .

[0003] Typically, an electrical measuring shunt 1 consists of a calibrated resistive element 2, electrodes 3, 3', electrical connection terminals 4, 4', and measuring terminals 5, 5' defined on the electrodes 3, 3' respectively. The electrical connection terminals 4, 4' allow the passage of an electric current under the influence of a potential difference (voltage), which can be measured between the measuring terminals 5, 5'. Using the calibrated resistance value of the resistive element 2 and the voltage measurement across the measuring terminals, the electric current flowing through the electrical measuring shunt 1 can be deduced using Ohm's law.

[0004] The calibration of resistive element 2 is generally achieved by localized machining of the resistive element. For example, see WO 2017 / 065144 A1, which proposes making notches on resistive element 2 while it is electrically powered, in order to adjust its resistance value (in-situ calibration during measurement). Alternatively, the calibration of resistive element 2 can also be performed by mechanical adjustment during the assembly of the electrical shunt 1, by geometrically controlling the contact surface between two resistive elements. This is, for example, what is proposed in WO 2019 / 190144 A1 or WO 02 / 56320 A1.

[0005] The resistive element 2 is generally made of a copper-based alloy. The copper-based materials used for resistive element 2 typically have resistivities between 20 and 50 µΩ·cm, and temperature coefficients of resistance (resistivity variation with temperature) of up to ±30 × 10⁻⁶ Ω·K⁻¹. The composition of these alloys (copper, manganese, nickel, tin, iron, silicon) gives them electrical characteristics that guarantee the accuracy and reliability of the measurement over an operating temperature range of 0°C to 175°C. See, for example, WO 2022 / 044611 A1 or WO 2022 / 030071 A1.

[0006] Furthermore, the resistive element 2 is usually brazed to the electrodes 3, 3' with silver 6, 6'. This brazing method with silver limits its use to certain materials. Consequently, the electrodes 3, 3' are primarily made of copper or a copper-based alloy. It should be noted that the assembly of the resistive element 2 with the electrodes 3, 3' has been the subject of numerous publications. Examples include WO 2011 / 068205 A1, WO 2017 / 110354 A1, and WO 2015 / 080333 A1.

[0007] The assembly of the electrical connection terminals 4, 4' to the electrodes 3, 3' has also been the subject of publications. Notable examples include WO 2019 / 097924 A1, WO2019 / 097925 A1 and KR10-2016-0101251, which include proposals for reducing or eliminating the contact resistance between the electrical connection terminals and the electrodes.

[0008] It should be noted that there are multiple ways to assemble the various components of an electrical measuring shunt, such as: pressure bonding, brazing, welding (electrical resistance, laser, electron beam), and metal casting. Each assembly method must be compatible with the materials (resistive element, electrode, and measuring terminal), ensure good electrical conductivity between the assembled components (minimizing contact resistance), and guarantee the mechanical strength of the electrical measuring shunt assembly.

[0009] It should also be noted that the geometries and dimensions of the resistive elements have an influence on the thermal and electrical behavior of the electrical measurement shunts.

[0010] Examples include solid bar shapes, shapes based on a multitude of thin bars (WO 2017 / 065144 A1, WO 2019 / 190144A1, CN209231398U), and rod or tube shapes (WO 2018 / 150870 A1, WO 2013 / 005824 A1, WO 2011 / 068205 A1). In particular, the tube shape helps to limit Joule heating losses by utilizing the skin effect during the passage of alternating current.

[0011] US 2018 / 174721 A1 discloses a resistor comprising a first electrode, a second electrode and a resistive element disposed between the first and second electrodes.

[0012] In all cases, the materials of the resistive elements are selected based on their electrical properties (resistivity and temperature coefficient of resistance), which in turn determines the choice of electrode materials, which are predominantly copper-based. Indeed, the resistive element and the electrodes must be compatible and possess compatible electrical and thermal properties, not to mention the induced contact resistance between the different components of the measuring shunt.

[0013] Furthermore, manufacturing processes (assembly and calibration techniques) limit the geometric and dimensional optimization of electrical measurement shunts. The contact areas between the resistive element, the electrodes, and the connection and measurement terminals must all be accessible to allow assembly by brazing, welding, or molding. In addition, machining the resistive element for calibration constitutes an extra post-manufacturing step.

[0014] One objective of the invention is to propose a method for manufacturing an electric current sensor that does not present at least one of the aforementioned disadvantages. Résumé de l'invention

[0015] To achieve this objective, the invention proposes a method for manufacturing an electric current sensor comprising the following steps: a) provide a substrate made of metal or metal alloy, b) make a non-through cavity in said substrate so that said cavity separates the substrate into two zones, c) make, by additive manufacturing, a resistive element in said cavity, d) anneal the assembly thus obtained, e) remove part of the substrate to leave only the resistive element between the two zones of the substrate, and f) define, within each zone, a connection terminal to obtain electrodes.

[0016] The process according to the invention may include at least one of the following additional steps, taken alone or in combination: The substrate supplied in step a) is made of Aluminium, Copper or a Copper-based alloy; the cavity made in step b) is obtained by machining the substrate; step c) is carried out by cold spraying, advantageously at a pressure below 15 bar; step d) is carried out at a temperature between 400 and 600 °C for a duration between 5 and 15 minutes; the process includes an additional step consisting of making a measuring terminal in each of the two electrodes; the resistive element does not undergo any machining steps, in particular to adapt the value of its resistivity; the substrate supplied in step a) is a solid cylinder; the substrate supplied in step a) is a solid parallelepiped; the sensor is an electrical shunt. Brève description des figures

[0017] Other objects and features of the invention will become clearer in the following description, made with reference to the accompanying figures, in which: There [ Fig. 2 ] represents a hollow cylindrical electrical shunt obtained using the manufacturing process according to the invention; The [ Fig. 3 ] represents a manufacturing process conforming to the invention of the electrical shunt shown on the [ Fig. 2 ] ; There [ Fig. 4a ] is a diagram representing an installation for implementing a low-pressure cold spray additive manufacturing process; The [ Fig. 4b ] is a diagram representing an installation for implementing a high-pressure cold spray additive manufacturing process; The [ Fig. 5a ] represents a substrate that can be used to initiate the manufacturing process according to the invention; The [ Fig. 5b ] represents the substrate of the [ Fig. 5a ] after being machined; The [ Fig. 5c ] represents the assembly formed after additive manufacturing deposition of a resistive element in a non-through orifice of the machined substrate of the [ Fig. 5d ] ; There [ Fig. 5d ] represents the electrical shunt finally obtained after annealing and drilling through the entire [ Fig 5c ] ; There [ Fig. 6 ] represents the electrical shunt after adding measuring terminals; The [ Fig. 7 represented an electrical shunt, of the "busbar" type, obtained with the manufacturing process according to the invention. Description détaillée de l'invention

[0018] The following description assumes that the electrical current sensor is an electrical shunt. However, the invention is not limited to the manufacture of an electrical shunt.

[0019] There figure 2 is an example of the realization of an SHE electrical shunt, in this case of hollow cylindrical shape, obtained according to the process according to the invention.

[0020] The electrical shunt (SHE) comprises a first PEL electrode, a second DEL electrode, and a resistive element (ER) between the two electrodes. Each PEL electrode has an associated connection terminal, BCE1 and BCE2 respectively, located at the ends of the electrical shunt. A measurement terminal, BM1 and BM2, is also provided on each PEL and DEL electrode. In this embodiment, both the PEL and DEL electrodes and the resistive element form hollow cylinders.

[0021] There figure 3 schematically represents the different stages of the manufacturing process of an electrical current sensor such as an SHE electrical shunt, in particular the one shown on the figure 2 namely: a) provide a metal or metal alloy SBT substrate, b) make a non-through CVT cavity in said substrate so that said cavity separates the substrate into two zones Z1, Z2, c) make, by additive manufacturing, a resistive element ER in said CVT cavity, d) anneal the assembly thus obtained at the end of step c), e) remove a part of the SBT substrate to leave only the resistive element ER between the two zones Z1, Z2 of the substrate, and f) define, within each zone Z1, Z2, a connection terminal BCE1, BCE2 to obtain said electrodes PEL, DEL.

[0022] The SBT substrate provided in step a) can be made of aluminum, copper, or a copper-based alloy, and more generally, any electrically conductive metal or metal alloy. The process according to the invention, due to the use of an additive manufacturing step, allows, in particular, the use of a wider range of metals or metal alloys, while limiting the contact resistance between the resistive element (ER) and the electrodes (PEL, DEL). It is therefore particularly possible to use aluminum, which has the advantage of being much lighter than copper-based alloys. This can be important for certain applications.

[0023] The substrate provided in step a) is represented on the figure 5a It is a solid cylinder.

[0024] The non-through CVT cavity produced in step b) is obtained, for example, by machining the SBT substrate. This will notably be the case when a solid cylindrical substrate is provided in step a), from which material will then be removed to obtain the desired final shape of the SHE electrical shunt. Since the CVT cavity is non-through, a POR portion of the substrate remains at this stage, connecting two zones Z1 and Z2 of the same substrate, which are located on either side of the CVT cavity.

[0025] According to one embodiment, steps a) and b) can be combined by additively manufacturing the SBT substrate to the desired shape. This can be done using a process called "Cold Spray" (or "plongement à froid" in French), or a process called "direct energy deposition".

[0026] At the end of step b), we obtain a substrate as defined in the figure 5b As can be seen in this figure, the substrate includes a TM retaining rod which is only used to manipulate the SBT substrate during certain stages of the manufacturing process. This TM retaining rod is intended to disappear during the remainder of the manufacturing process.

[0027] To implement step c), various additive manufacturing techniques are possible.

[0028] The "Cold Spray" process, also known as "Gas Dynamic Spraying" or "Kinetic Spraying Process" in English, can be advantageously used. This process is a coating deposition method based on the supersonic projection of solid powder at a temperature below the melting point of the materials forming the powder grains. The kinetic energy acquired by the powder grains plastically deforms the constituent materials, ensuring coating adhesion. The temperatures involved in this process are lower than those used in other thermal spraying processes.

[0029] We have represented on the figure 4a , an installation to implement a "Cold Spray" deposition process, operating at low pressure (better known by the acronym LPCS for "Low Pressure Cold Spray" according to Anglo-Saxon terminology).

[0030] More specifically, the installation includes a CMP compressor that injects a carrier gas, such as air or nitrogen, into a heater or heat exchanger (ECH). The exiting gas is thus pressurized, typically to pressures below 15 bar (low pressure), and heated to a temperature typically below 1000°C, and in any case below the melting point of the material forming the powder grains, before entering a TY nozzle, typically a de Laval nozzle. The TY nozzle expands the pre-heated and pressurized gas, thereby accelerating the gas jet to supersonic speed. A powder reservoir (RES) allows powder, containing grains of the chosen material, to be injected into the TY nozzle, for example, downstream of the nozzle throat.Upon exiting the nozzle, the powder is projected against an SBT substrate to deposit an RVT coating, which can be in the form of one or more successive layers. Furthermore, each layer of the coating can be deposited in various ways, for example, in a spiral, in rings of different diameters, or along parallel generatrices, etc. Typically, particles from 5 to 50 µm can be projected at speeds of approximately 600 m / s. LPCS is generally used for projecting "soft" materials. The projected material, in powder form, can be mixed with alumina (also in powder form) to increase the yield and density of the deposit.

[0031] Regarding LPCS, one can, for example, refer to the article by Shuo Yin, Pasquale Cavaliere, Barry Aldwell, Richard Jenkins, Hanlin Liao, Wenya Li, Rocco Lupoi, “Cold spray additive manufacturing and repair: Fundamentals and applications”, Additive Manufacturing, Volume 21, 2018, Pages 628-650, ISSN 2214-8604, https: / / doi.org / 10.1016 / j.addma.2018.04.017.

[0032] We have represented on the figure 4b , another installation to implement a "Cold Spray" deposition process, operating at high pressure (better known by the acronym HPCS for "High Pressure Cold Spray" according to Anglo-Saxon terminology).

[0033] More specifically, the installation includes a pressurized gas cylinder (BGP) that injects a carrier gas, such as air, nitrogen, or helium, into two parallel circuits. One circuit contains a heater or heat exchanger (ECH), while the other contains a powder reservoir (RES) designed to inject powder into the relevant circuit. The two circuits are then combined before entering a nozzle (TY), such as a de Laval nozzle. The gas from the circuits is thus pressurized, typically to pressures exceeding 15 bar (high pressure), and heated to temperatures that can exceed 1000°C while remaining below the melting point of the material forming the powder grains, before entering the nozzle. The nozzle expands the pre-heated and pressurized gas, thereby accelerating the gas jet to supersonic speed.Upon exiting the TY nozzle, the powder is projected against an SBT substrate to deposit an RVT coating, which can be in the form of one or more successive layers. Furthermore, each layer of the RVT coating can be deposited in various ways, for example, in a spiral, in rings of different diameters, or along parallel generatrices, etc. Typically, particles from 5 to 50 µm can be projected at speeds exceeding 1000 m / s. HPCS is generally used for projecting "hard" materials, such as titanium.

[0034] In the applications targeted by the invention, a low-pressure (LPCS) type cold spray system, typically operating between 4 and 10 bar and more particularly between 4 and 8 bar, can advantageously be used with a powder having a particle size between 5 and 25 µm. Furthermore, the deposition of this powder is then advantageously carried out at a temperature between 400°C and 600°C. The carrier gas used to propel the powder against the substrate, such as air, is particularly well-suited.

[0035] The constituent material of the powder, and therefore of the resistive element ER, can be a metal, for example copper, nickel, aluminum, or zinc, or a copper-based metal alloy, for example manganin, noventin, zeranin, or constantan. In practice, the use of manganin, with a particle size between 5 and 25 µm, is particularly well-suited for the applications intended within the scope of the invention, especially for the electrical shunt SHE shown in the figure. figure 2 In particular, this manganin can then be co-sprayed with alumina (advantageously with a particle size of 25 µm or less to increase the yield and density of the deposit). In the case of co-spraying, the amount of alumina, which is not zero, can represent up to 40% by mass of the alumina + manganin powder mixture. The increased yield means that the ratio between the amount of material deposited and the amount of material sprayed increases. The increased density of the deposit reduces the presence of defects (porosity, cracks, etc.) and therefore improves the mechanical strength and / or the electrical and thermal properties of the deposit.We can also plan a sandblasting step with large particle size alumina powder, for example 250 microns, before the projection of the powder to manufacture the resistive element ER in order to increase the roughness of the substrate and consequently the mechanical adhesion of the resistive element ER on the SBT substrate intended to form the PEL, DEL electrodes.

[0036] Alternatively, still within the scope of the applications targeted by the invention, one can start with a powder having a particle size between 15 and 45 µm by operating at high pressure, namely between 10 and 60 bar. The associated temperatures can then be between 400 and 600°C.

[0037] In general, still within the framework of the applications targeted by the invention, it is therefore possible to operate with a "Cold Spray" type process with a pressure ranging from 4 to 60 bars (low pressure ranging from 4 to 10 bars or high pressure ranging from 10 to 60 bars), with temperatures likely to cover a wide range from 20°C to 1000°C, in particular depending on the nature of the material forming the powder (listed above) and its particle size (likely to range from 5 to 65 µm), with a carrier gas such as air, Argon or Helium.

[0038] Additive manufacturing techniques other than "Cold Spray" can be used. For example, additive manufacturing of the resistive element ER can be considered using a technique called "Direct Energy Deposition" (DED) and / or a technique called "Laser Powder Bed Fusion (FLPL)" which, like the "Cold Spray" technique, allow control and variation of the deposit composition during manufacturing.

[0039] Several strategies for obtaining the resistive element ER are then possible: Resistive alloy deposition (Cold Spray, DED, FLPL): the composition and properties are fixed. Combinatorial deposition with direct melting (DED, FLPL) allows the creation of a custom alloy with remelting of alloy precursors (e.g., Cu, Mn, Ni, Sn, Fe, Si). Combinatorial deposition with localized post-processing ("Cold Spray" + post-treatment by friction or laser): allows obtaining a deposit containing all alloy precursors and applying post-treatment to obtain the desired electrical properties in a localized manner.

[0040] Thus, the composition and composition gradients of resistive elements are determined according to the electrical properties sought without restricting themselves to the strict (commercial) alloys generally used.

[0041] At the end of step c), we arrive at a set such as is represented on the figure 5c .

[0042] The annealing performed in step d) can aim to restore the mechanical and electrical properties of the materials or to relieve mechanical stresses and improve the coating's durability. Depending on the case, the annealing conditions differ. For example, annealing can be carried out at a temperature between 150 and 300°C for 15 to 60 minutes to restore the mechanical and electrical properties of the materials (restoration annealing). Similarly, annealing can be carried out at a temperature of around 300°C for an hour or more to relieve mechanical stresses (recrystallization annealing) and improve the coating's durability. Annealing can be performed in air or under a controlled atmosphere.Typically, for copper-based materials (such as manganin), annealing can be carried out under air or controlled atmosphere, at high temperatures up to 600°C (recrystallization annealing), or at lower temperatures of around 200°C (restoration annealing), bearing in mind that it is necessary to take into account in parallel the melting temperature of the material forming the substrate (for example for aluminium, the melting temperature is 660°C but it can nevertheless begin to flow under stress from 450°C).

[0043] Once the annealing is complete, a portion of the SBT substrate is removed in step e) of the process according to the invention, leaving only the resistive element ER between the two zones Z1 and Z2 of the substrate. Applied to the fabrication of the SHE electrical shunt of the figure 2 This step consists more specifically of drilling through the assembly recovered after annealing. This removes the TM retaining rod, as well as the SBT substrate connection zone between these two zones. Incidentally, in accordance with step f) of the process according to the invention, this also allows the creation of the two connection terminals BCE1, BCE2 on the Z1, Z2 zones in order to define the PEL, DEL electrodes.

[0044] The set obtained at the end of step f) is represented on the figure 5d .

[0045] It only remains advantageously, in an additional step, to create measurement terminals BM1, BM2. We then obtain the electrical shunt shown on the figure 2 .

[0046] On the figure 6 We have represented different parameters allowing the design of the SHE electrical shunt of the figure 2 before the drilling step (step e) above of the process according to the invention) of the assembly obtained after annealing: D denotes the outside diameter of the PEL, DEL electrodes with 3.5mm < D < 50mm; d denotes the inside diameter of the PEL, DEL electrodes with 1.5mm < d < 20mm and d max = D / 1.75; h denotes the thickness of the resistive element ER, with 1 mm < h < (D - d) / 2; A denotes the angle of inclination given to the cavity with 1° < a < 90°, preferably A such that 30° < A < 60°; and L denotes the length of the electrical shunt with 5 mm < L < 100 mm.

[0047] The values ​​are adapted to the application.

[0048] Other geometries than the one represented on the figure 2 are achievable with the process according to the invention.

[0049] Thus, as an additional, non-limiting example, it is possible to manufacture a SHE' electrical shunt of the "busbar" type as shown in the figure 6 .

[0050] In this particular case, step a) begins with a solid, parallelepiped-shaped substrate, into which a cavity of the desired shape can be formed in step b), for example, by machining. Here too, alternative methods could be used to obtain the substrate with its non-through cavity. Step c) then repeats what has been described previously, as do steps d), e), and f), regardless of the variants considered, which are also applicable to this other geometry. At the end of step f), the electrical shunt SHE' is defined with its electrodes PEL' and DEL', which are thus equipped with connection terminals BCE1' and BCE2', the electrodes being connected to each other by the single resistive element ER'. It is then advantageous to also fabricate measuring terminals BM1' and BM2', as can be seen in the diagram. figure 6 .

[0051] The electrical shunt SHE, SHE' obtained within the framework of the invention can, in particular, be used to measure the electrical consumption or the state of charge of batteries in the following fields: transportation (car, aeronautics, rail, aerospace), metrology, industry, and construction. This electrical shunt is more generally used to form any alternating (AC) or direct (DC) current measurement probe for electronics (10 to 500 A). Exemple de réalisation : fabrication of a hollow cylindrical electrical shunt

[0052] First, a solid, cylindrical, aluminum SBT substrate is provided ( figure 5a ), in accordance with step a) of the process according to the invention.

[0053] The substrate is then machined to define a non-through CVT cavity, in accordance with step b) of the process confirming the invention, in this case trapezoidal in cross-section, around the entire periphery of the substrate. Furthermore, here, one end of the substrate is also machined to define a retaining rod TM useful for its handling during the manufacturing process ( figure 5b Apart from the TM retaining rod, the Z1 and Z2 zones of the substrate located on either side of the CVT cavity are those intended to form the first and second electrodes. These Z1 and Z2 zones are connected by a POR portion of substrate, in this case cylindrical in shape, which is subsequently removed during the manufacturing process.

[0054] Next, additive manufacturing of the resistive element ER is carried out in the CVT cavity, in accordance with step c) of the process according to the invention.

[0055] For this purpose, the additive manufacturing process used is the "Cold Spray" process of the LPCS (low pressure) type. It starts with a powder mixture (compatible with the "Cold Spray" process) of manganin with a particle size of 5 to 50 µm and alumina with a particle size of 5 to 25 µm, the alumina representing 20% ​​by mass of the powder mixture. The process is carried out at a pressure of 8 bar and a temperature of 400 °C, in air. The substrate is rotated continuously at 60 rpm at a rotational speed of 30 mm / min. The coating is deposited in several successive layers, and for each layer, the deposit is made in the form of helicals. We take advantage of this additive manufacturing operation by "Cold Spray" to perform a preliminary sandblasting of the substrate surface, in this case with alumina powder with a particle size of 250 microns.Sandblasting promotes the adhesion of the deposit made during additive manufacturing by "Cold Spray" and therefore ultimately the mechanical strength of the resistive element on the substrate, in other words, ultimately on the electrodes (. figure 5c ).

[0056] With additive manufacturing, the resistive element (RE) is dimensioned to obtain a defined resistivity value. This eliminates, compared to prior art, the need for a subsequent machining step (rework) of the resistive element to adjust its resistance.

[0057] The assembly obtained at this stage of manufacturing is then annealed, in accordance with step d) of the process according to the invention. This annealing serves to restore the mechanical and electrical properties of the various materials. In this case, it is an annealing for 1 hour at 300°C.

[0058] Then, according to step e) of the method according to the invention, a portion of the SBT substrate is removed, leaving only the resistive element ER between the two zones Z1 and Z2 of the substrate. In practice, the substrate is drilled through along its longitudinal axis AL. This operation eliminates the portion POR of the substrate that connected the two zones Z1 and Z2. The desired hollow cylindrical shape is thus obtained.

[0059] In this particular case, drilling through the substrate simultaneously allows step f) to be carried out according to the method of the invention. This allows the connection terminals to be generated at the end of each of the zones Z1 and Z2, ultimately forming the first and second electrodes. Furthermore, in this embodiment, the retaining rod TM is also removed by this same operation.

[0060] The PEL and DEL electrodes and the ER resistive element are defined at this stage, as are the electrical connection terminals BCE1 and BCE2 ( figure 5d ).

[0061] We can then advantageously create measuring terminals BM1 and BM2. To create these measuring terminals, we can drill a tapped hole to attach a lug with a screw. We can also drill a hole, for example a conical one, to house a spring-loaded contactor.

[0062] End of example.

Claims

1. A method for manufacturing an electric current sensor (SHE) comprising the following steps: a) providing a metal or metal alloy substrate (SBT), b) making a non-through cavity (CVT) in said substrate so that said cavity separates the substrate into two areas (Z1, Z2), c) producing a resistive element (ER) in said cavity (CVT) by additive manufacturing, d) annealing the resulting assembly, e) removing a part of the substrate (SBT) to leave only the resistive element (ER) between the two areas (Z1, Z2) of the substrate, and f) defining, within each area (Z1, Z2), a connection terminal (BCE1, BCE2) to obtain electrodes (PEL, DEL).

2. The method for manufacturing an electrical current sensor according to claim 1, wherein the substrate provided in step a) is made of Aluminum, Copper or a Copper-based alloy.

3. The method for manufacturing an electric current sensor according to one of the preceding claims, wherein the cavity (CVT) produced in step b) is obtained by machining the substrate (SBT).

4. The method for manufacturing an electric current sensor according to one of the preceding claims, wherein step c) is carried out by cold spraying, advantageously at a pressure of less than 15 bar.

5. The method for manufacturing an electric current sensor according to one of the preceding claims, wherein step d) is performed at a temperature of between 400 and 600°C for a period of between 5 and 15 minutes.

6. The method for manufacturing an electrical current sensor according to one of the preceding claims, comprising an additional step consisting in making a measurement terminal (BM1, BM2) in each of the two electrodes (PEL, DEL).

7. The method for manufacturing an electric current sensor according to one of the preceding claims, wherein the resistive element (ER) does not undergo any machining step, in particular to adapt the value of its resistivity.

8. The method for manufacturing an electrical current sensor according to any of the preceding claims, wherein the substrate (SBT) provided in step a) is a solid cylinder.

9. The method for manufacturing an electrical current sensor according to one of claims 1 to 7, wherein the substrate (S) provided in step a) is a solid parallelepiped.

10. The method for manufacturing an electrical current sensor according to one of the preceding claims, wherein said sensor is an electrical shunt.

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