Method for manufacturing an electric current sensor by additive manufacturing

Abstract

TITLE: Method for manufacturing an electric current sensor by additive manufacturing. The invention relates to a method for manufacturing an electric current sensor (ECS) comprising the following steps: a) providing a substrate (SBT) made of metal or metal alloy, b) creating a non-through cavity (CVT) in said substrate such that said cavity separates the substrate into two zones (Z1, Z2), c) creating, by additive manufacturing, a resistive element (ER) in said cavity (CVT), d) annealing the assembly thus obtained, e) removing a portion 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 said electrodes (PEL, DEL). Figure for the abstract: Fig. 2

Description

Title of the invention: Method for manufacturing an electric current sensor by additive manufacturing. Technical field of the invention

[0001] The invention relates to the field of manufacturing electric current sensors, for example an electric shunt. Technical background

[0002] A known electrical shunt is shown in [Fig.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 effect of a potential difference (voltage), which can be measured between the measuring terminals 5, 5'. Using the calibrated value of the resistance 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 the resistive element 2 is generally achieved by localized machining of the resistive element. For example, reference may be made to WO 2017 / 065144 Al, which proposes making notches on the resistive element 2 while it is electrically powered, in order to adjust its resistance value (in-situ calibration during measurement). Alternatively, the calibration of the resistive element 2 can also be carried out 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 Al or WO 02 / 56320 AL

[0005] The resistive element 2 is generally made of a copper-based alloy. The copper-based materials used for the resistive element 2 typically have resistivities between 20 and 50 pΩ·cm, and maximum temperature coefficients of resistance (resistivity variation with temperature) of ±30 × 10⁶ 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 from 0°C to 175°C. Reference may be made, for example, to WO 2022 / 044611 Al or WO 2022 / 030071 AL

[0006] Furthermore, the resistive element 2 is usually brazed to the electrodes 3, 3' with silver 6, 6'. This brazing assembly 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 element resistive 2 with electrodes 3, 3', has been the subject of numerous publications. Examples include WO 2011 / 068205 Al, WO 2017 / 110354 Al and WO 2015 / 080333 Al.

[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 Al, WO2019 / 097925 Al 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 elements of the 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 elements (minimize 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] Thus, solid bar shapes, shapes based on a multitude of thin bars (WO 2017 / 065144 Al, WO 2019 / 190144A1, CN209231398U), or rod or tube shapes (WO 2018 / 150870 Al, WO 2013 / 005824 Al, WO 2011 / 068205 Al) are found. In particular, the tube shape makes it possible to limit Joule effect losses by taking advantage of the skin effect during the passage of alternating currents.

[0011] In all cases, since the materials of the resistive elements are selected based on their electrical properties (resistivity and temperature coefficient of resistance), this influences the choice of electrode materials, which are predominantly copper-based. Indeed, the resistive element and the electrodes must be able to be assembled and possess compatible electrical and thermal properties, not to mention the induced contact resistance between the different elements of the measuring shunt.

[0012] Furthermore, manufacturing processes (assembly and calibration techniques) are limiting factors for 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 to perform calibration constitutes an additional post-manufacturing step.

[0013] An 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. Summary of the invention

[0014] To achieve this objective, the invention proposes a method for manufacturing an electric current sensor comprising the following steps: a) providing a substrate made of metal or metal alloy, b) creating a non-through cavity in said substrate such that said cavity separates the substrate into two zones, c) creating, by additive manufacturing, a resistive element in said cavity, d) annealing the assembly thus obtained, e) removing a portion 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 said electrodes.

[0015] The process according to the invention may include at least one of the following additional steps, taken alone or in combination:

[0016] - the substrate provided in step a) is made of Aluminium, Copper or a base alloy Copper;

[0017] - the cavity produced in step b) is obtained by machining the substrate;

[0018] - step c) is carried out by cold spraying, advantageously under pressure less than 15 bar;

[0019] - step d) is carried out at a temperature between 400 and 600 °C for a duration between 5 and 15 minutes;

[0020] - the method includes an additional step consisting of making a terminal of measurement in each of the two electrodes;

[0021] - the resistive element does not undergo any machining steps, in particular to adapt the its resistivity value;

[0022] - the substrate provided in step a) is a solid cylinder;

[0023] - the substrate provided in step a) is a solid parallelepiped;

[0024] - the sensor is an electrical shunt. Brief description of the figures

[0025] Other objects and features of the invention will become clearer in the following description, made with reference to the accompanying figures, in which:

[0026] Fig. 2 represents an electrical shunt, of hollow cylindrical shape, obtained with the manufacturing process according to the invention;

[0027] [Fig.3] represents a manufacturing process according to the invention of the electrical shunt shown in [Fig.2];

[0028] Fig. 4a is a diagram representing an installation for implementing a low-pressure cold spray additive manufacturing process;

[0029] Fig. 4b is a diagram representing an installation for implementing a high-pressure cold spray additive manufacturing process;

[0030] Fig. 5a represents a substrate that can be used to start the manufacturing process according to the invention;

[0031] Fig. 5b represents the substrate of Fig. 5a after it has been machined;

[0032] Figure 5c represents the assembly formed after additive manufacturing deposition of a resistive element in a non-through orifice of the machined substrate of [Fig.5d];

[0033] Fig. 5d represents the electrical shunt finally obtained after annealing and drilling through and through the whole of Fig. 5c;

[0034] Fig. 6 represents the electrical shunt after adding measuring terminals;

[0035] Figure 7 shows an electrical shunt, of the "busbar" type, obtained with the process of manufacture according to the invention. Detailed description of the invention

[0036] The following description is given in the case where the electric current sensor is an electrical shunt. However, the invention is not limited to the manufacture of an electrical shunt.

[0037] Fig. 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.

[0038] The electrical shunt SHE comprises a first PEL electrode, a second DEL electrode, and a resistive element ER between the two PEL and DEL electrodes. Each PEL electrode has an associated connection terminal, BCE1 and BCE2 respectively, located at the ends of the electrical shunt. A measurement terminal, BMI 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.

[0039] Figure 3 schematically represents the different stages of the manufacturing process for an electric current sensor such as an electrical shunt (SHE), in particular the one shown in Figure 2, namely: a) providing an SBT substrate made of metal or metal alloy, b) creating a non-through CVT cavity in said substrate such that said cavity separates the substrate into two zones Z1, Z2, c) creating, by additive manufacturing, a resistive element ER in said CVT cavity, d) annealing the assembly thus obtained at the end of step c). e) remove 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 the said electrodes PEL, DEL.

[0040] The SBT substrate provided in step a) can be made of aluminum, copper, or a copper-based alloy, and more generally of 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.

[0041] The substrate provided in step a) is shown in [Fig.5a]. It is a solid cylinder.

[0042] The non-through-hole 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-hole, 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.

[0043] 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 by a process called "Cold Spray" (or "plongement à froid" in French), or by a process called "direct energy deposition".

[0044] At the end of step b), a substrate is obtained as defined in [Fig. 5b]. As can be seen in this figure, the substrate includes a retaining rod TM which is only used to manipulate the substrate SBT during certain steps of the manufacturing process. This retaining rod TM is intended to disappear during the remainder of the manufacturing process.

[0045] To implement step c), various additive manufacturing techniques are conceivable.

[0046] The "Cold Spray" process, or "plongement à froid" in French, can thus be advantageously used. The "Cold Spray" process (also known as "Gas Dynamic Spraying" or "Kinetic Spraying Process" in English) is a coating deposition process based on the supersonic projection of solid powder at a temperature below the melting point of the materials forming the grains. Powder. It is the kinetic energy acquired by the powder grains that plastically deforms the materials they constitute, ensuring the adhesion of the coating. The temperatures involved in this process are lower than those involved in other thermal spraying processes.

[0047] Figure 4a shows an installation for implementing 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).

[0048] More specifically, the installation includes a CMP compressor for injecting a carrier gas, for example 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 nozzle TY, typically a de Laval nozzle. The TY nozzle expands the preheated and pressurized gas, thereby accelerating the gas jet's velocity to supersonic speed. A powder reservoir RES allows powder, along with 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 pm 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.

[0049] With regard to LPCS, reference may be made for example to the article by Shuo Yin, Pasquale Cavalière, 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.

[0050] Figure 4b shows another installation for implementing 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).

[0051] More specifically, the installation includes a BGP pressurized gas cylinder for injecting a carrier gas, for example air, nitrogen or helium, into two parallel circuits, one of which includes a heater or heat exchanger The other circuit, ECH, contains a powder reservoir (RES) designed to inject powder into the relevant circuit. The two circuits are then combined before entering a TY nozzle, 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 TY nozzle. The TY nozzle expands the preheated 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 pm can be projected at speeds exceeding 1000 m / s. HPCS is generally used for projecting "hard" materials, such as titanium.

[0052] In the context of the applications covered by the invention, a low-pressure (LPCS) type "Cold Spray" can advantageously be used, typically between 4 and 10 bar and more particularly between 4 and 8 bar, 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 project the powder against the substrate, such as air, is particularly well suited.

[0053] 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 contemplated within the scope of the invention, in particular for the electrical shunt SHE shown in [Fig. 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 of the amount of material deposited to the amount of material sprayed increases.Increasing the deposit density reduces the presence of defects (porosity, cracks, etc.) and therefore improves the mechanical strength and / or the electrical and thermal properties of the deposit. A sandblasting step using powder can also be included. of alumina of large particle size, 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.

[0054] Alternatively, still within the scope of the applications covered 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.

[0055] Generally speaking, still within the framework of the applications covered 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 pm), with a carrier gas such as air, Argon or Helium.

[0056] Additive manufacturing techniques other than "Cold Spray" can be used. Thus, 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 composition of the deposit during manufacturing.

[0057] Several strategies for obtaining the resistive element ER are then possible: - Deposition of the resistive alloy (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 reflows of alloy precursors (e.g., Cu, Mn, Ni, Sn, Fe, Si). - Combinatorial deposition with localized post-process (“Cold Spray” + post-treatment by friction or Laser): allows obtaining a deposit containing all the alloy precursors and applying a post-treatment to obtain the desired electrical properties in a localized manner.

[0058] 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.

[0059] At the end of step c), we arrive at an ensemble such as represented on [Fig.5c].

[0060] The annealing carried out in step d) can aim to restore the mechanical and electrical properties of the materials or to relieve mechanical stresses and increase the durability of the deposit. Depending on the case, the annealing conditions are not the same. Thus, the Annealing can be carried out at a temperature between 150 and 300°C for a duration of 15 to 60 minutes to restore the mechanical and electrical properties of materials (restoration annealing). Similarly, annealing can be carried out at a temperature of around 300°C for a duration of 1 hour or more to relieve mechanical stresses (recrystallization annealing) and increase the durability of the coating. 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 the melting temperature of the substrate material must also be taken into account (for example, for aluminium, the melting temperature is 660°C but it can nevertheless begin to flow under stress from 450°C).

[0061] Once annealing has been carried out, in step e) of the process according to the invention, a portion of the SBT substrate is removed, leaving only the resistive element ER between the two zones Z1, Z2 of the substrate. Applied to the fabrication of the electrical shunt SHE of [Fig. 2], this step consists more precisely of drilling through the assembly recovered after annealing. This removes the retaining rod TM, but also the connection zone of the SBT substrate between these two zones. This also incidentally allows, in accordance with step f) of the process according to the invention, the creation of the two connection terminals BCE1, BCE2 on the zones Z1, Z2 in order to define the electrodes PEL, DEL.

[0062] The set obtained at the end of step f) is represented in [Fig.5d].

[0063] It only remains advantageously, in an additional step, to create measurement terminals BMI, BM2. We then obtain the electrical shunt represented in [Fig.2].

[0064] In [Fig.6], various parameters are shown allowing the design of the electrical shunt SHE of [Fig.2] before the drilling step (step e) above of the process according to the invention) of the assembly obtained after annealing: - D designates the outside diameter of the PEL, DEL electrodes with 3.5mm < D < 50mm; - d designates the inner diameter of the PEL, DEL electrodes with 1.5mm < d < 20mm and dmax = 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°, of preference A such that 30° < A < 60°; and - L denotes the length of the electrical shunt with 5 mm < L < 100 mm.

[0065] The values ​​are adapted to the application.

[0066] Other geometries than that shown in [Fig.2] can be achieved with the process according to the invention.

[0067] Thus, as an additional non-limiting example, it is possible to manufacture a SHE' electrical shunt of the "busbar" type as shown in [Fig.6].

[0068] In this particular case, step a) begins with a solid parallelepiped-shaped substrate, in which a cavity of the desired shape can be formed in step b), for example, by machining. Here too, another method 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', DEL', thus equipped with connection terminals BCE1', BCE2', the electrodes being connected to each other by the single resistive element ER'. Measurement terminals BMI', BM2' are then advantageously also produced, as can be seen in [Fig. 6].

[0069] 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).

[0070] Example of an embodiment j. fabrication of a hollow cylindrical electrical shunt

[0071] First, a solid, cylindrical, aluminium SBT substrate ([Fig.5a]) is provided, in accordance with step a) of the process according to the invention.

[0072] The substrate is then machined to define a non-through CVT cavity, in accordance with step b) of the process according to the invention, in this case trapezoidal in cross-section, around the entire periphery of the substrate. Furthermore, one end of the substrate is also machined to define a retaining rod TM useful for its handling during the manufacturing process ([Fig. 5b]). Apart from the retaining rod TM, 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 the substrate, in this case cylindrical in shape, which is subsequently removed during the manufacturing process.

[0073] 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.

[0074] For this purpose, the additive manufacturing process used is the process known as "Cold Spray" 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, under air. The substrate is rotated. The process continues at 60 rpm at a rotational speed of 30 mm / min. The coating is deposited in several successive layers, each layer being helical in shape. This additive manufacturing operation using cold spray is used to perform preliminary sandblasting of the substrate surface, in this case with 250-micron alumina powder. Sandblasting promotes adhesion of the coating applied during the cold spray additive manufacturing process and thus ultimately improves the mechanical strength of the resistive element on the substrate, or in other words, on the electrodes ([Fig. 5c]).

[0075] With additive manufacturing, the resistive element ER is dimensioned to obtain a defined value of its resistivity. Compared to the prior art, this eliminates the need for a subsequent machining step (rework) of the resistive element to adapt it.

[0076] 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 of Ih at 300°C.

[0077] 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, 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, Z2. The desired hollow cylindrical shape is thus obtained.

[0078] In this particular case, drilling through the substrate simultaneously allows step f) to be carried out according to the method of the invention. Indeed, this makes it possible to generate the connection terminals at the end of each of the zones Z1, Z2, ultimately forming the first and second electrodes. Furthermore, in this embodiment, the retaining rod TM is also removed by this same operation.

[0079] The electrodes PEL, DEL and the resistive element ER are defined at this stage, as are the electrical connection terminals BCE1, BCE2 ([Fig.5d]).

[0080] It is then advantageous to create BMI and BM2 measuring terminals. To create these measuring terminals, a tapped hole can be made to attach a lug using a screw. A hole, for example conical, can also be made to house a spring-loaded contactor.

[0081] End of example.

Claims

Demands

1. A method for manufacturing an electric current sensor (SHE) comprising the following steps: a) providing a substrate (SBT) 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 portion 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).

2. A method for manufacturing an electric current sensor according to claim 1, wherein the substrate supplied in step a) is made of Aluminium, Copper or a Copper-based alloy.

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

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

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

6. Method of manufacturing an electric current sensor according to any one of the preceding claims, comprising an additional step of making a measuring terminal (BMI, BM2) in each of the two electrodes (PEL, DEL).

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

8. A method for manufacturing an electric current sensor according to any one of the preceding claims, wherein the substrate (SBT) supplied in step a) is a solid cylinder.

9. Method of manufacturing an electric current sensor according to any one of claims 1 to 7, wherein the substrate (S) supplied in step a) is a solid parallelepiped.

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

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